Mulberry leaf is a kind of medicinal and edible homologous plant source with a long history. It is rich in protein, amino acids, fatty acids, vitamins, minerals. In addition, it is also rich in bioactive substances, such as deoxynojirimycin, quercetin, chlorogenic acid, benzoic acid, rutin, etc., which have various pharmacological activities such as antioxidant, immunity enhancement and antiphlogosis, and attracted more attention. It is found that mulberry leaf products could be used as an unconventional feed protein raw materials and additives, and have positive effects on nutrient digestion and absorption, sugar and lipid metabolism, health status and product quality of aquatic animals. In this paper, the nutritional value of mulberry leaf and its application in aquatic feeds were reviewed in order to provide reference for the application of mulberry leaf in aquatic feed and the comprehensive utilization and development of mulberry leaf resources.

The hepatopancreas of common carp (Cyprinus carpio) will produce insulin resistance after high glucose load, which has become a key restriction factor limiting the effect of carbohydrate on protein sparing. Studies on the mechanism of its production mainly focus on protein-coding genes such as insulin signaling pathways. At present, aiming at this limiting factor, some nutrition mitigation strategies have been explored in the aspects of carbohydrate source, carbohydrate level, feeding mode and different nutrient intervention in common carp growth stage. There is a lack of understanding of the mechanism of hyperglycemic nutrient perception in common carp based on cellular level and epigenetic level. It is urgent to further clarify the physiological characteristics and special regulatory mechanisms of glucose metabolism in common carp, and explore functional nutrients or breeding strategies that can alleviate insulin resistance in fish. In view of this, this paper summarized the research progress in this direction from three aspects, the generation mechanism of hepatopancreas insulin resistance, nutritional strategies and their potential mechanisms for alleviating hepatopancreas insulin resistance and the prospect of future research, so as to enrich the understanding of the regulatory mechanism of hepatopancreas insulin resistance in common carp. It lays a solid theoretical foundation for improving starch and other carbohydrate materials application and sparing feed protein raw materials such as fish meal and soybean meal.

Modern pig and chicken breeds have the characteristics of fast growth rate and high feed utilization rate, but the body disease resistance is weak, easy to be attacked by pathogenic microorganisms such as bacteria and viruses. Chlorogenic acid is a kind of plant polyphenol, which is a phenolic acid composed of caffeic acid and quinic acid. Chlorogenic acid is also an effective component in Chinese traditional medicine honeysuckle and Eucommia. Chlorogenic acid has antibacterial, antiviral, anti-tumor, antioxidant and other biological effects, but also can reduce hypertension, hyperglycemia, hyperlipidemia and other chronic diseases. It has been widely used in the medical field. This paper summarized the basic properties and sources, metabolism and biosafety, biological functions of chlorogenic acid, and its application in pig and chicken production, in order to provide reference for the extensive application of chlorogenic acid in livestock and poultry production.

The potato (Solanum tuberosum L.), as the fourth largest food crop in the world, is cultivated in the temperate and subtropical regions of six continents, with an annual output of over 370 million tons. In recent years, the potato processing industry chain has generated an increasing number of by-products. These by-products, which are difficult to store but rich in nutrients, have brought dual challenges to resource utilization and environmental management. The unique digestive system of ruminants can effectively convert agricultural by-products into high-quality protein through microbial fermentation, which provides a promising idea for the sustainable utilization of potato by-products. Although different types of potato by-products still have problems such as solanine, mycotoxins, parasites and physical properties in actual feeding scenarios, if they can be applied to ruminant production, it can not only avoid environmental pollution and nutrient loss, but also save food and reduce feeding costs in the context of “human-animal competition for food”. However, existing studies lack a systematic classification of potato by-products and a comprehensive assessment of their nutritional components and feeding effects. This article lists the sources and differences in nutritional components of different types of potato by-products, proposes application schemes of potato by-products in ruminant production, and reviews the potential risks in actual production, with the aim of exploring the application effects of potato by-products in ruminant production and alleviating the problem of “human-animal competition for food”.

Fungal polysaccharides are a type of polysaccharide extracted from the mycelium, fruiting bodies and fermentation broth of fungi. They possess biological functions such as antioxidation, anti-inflammation, immune regulation, hypoglycemic and hypolipidemic, anti-tumor and intestinal microbiota regulation, and can be promoted and applied as feed additives in pig production. This article reviews the structural characteristics, biological functions and application research progress of fungal polysaccharides from edible and medicinal sources in pig production, with the aim of providing a reference for the utilization of fungal polysaccharides in pig production.

Epigallocatechin gallate (EGCG), the predominant bioactive compound in tea leaves, has attracted considerable attention in the field of livestock production due to its potent antioxidant and anti-inflammatory properties. As a natural and environmentally friendly antioxidant, EGCG has been used as a natural, green and highly effective antioxidant in human food and livestock and poultry diets. However, research on its precise metabolic effects and regulatory mechanisms in poultry remains relatively limited. Therefore, this paper reviewed the mechanism of antioxidant and anti-inflammatory effects of EGCG and its application in poultry production, aiming to provide a reference for the rational use of EGCG in poultry diets.

With the intensification of global warming, the problem of heat stress in dairy cows has become increasingly importance, adversely affecting animal health and production performance. When exposed to heat stress, dairy cows develop thermal tolerance to hot environment by reducing metabolic heat production and regulating body temperature. This article summarized the evaluation indicators of heat tolerance in dairy cows from various aspects, including environment, physiology, productivity and blood biochemical indicators; it also explored the multiple factors influencing heat tolerance in dairy cows such as animal, environment and nutrition factors; furthermore, it elaborated the mechanisms by which dairy cows adapt to the hot environment, involving behavior, endocrine regulation, metabolic mechanisms, and changes in the community of rumen microorganisms. This review aims to understand the heat tolerance in dairy cows and its underlying mechanisms, and is expected to provide references for improving the health status and production performance of dairy cows under heat stress environments.

Japanese seabass (Lateolabrax japonicus), a cornerstone of China’s marine aquaculture industry, achieved a production volume of 246 900 tons in 2023, securing its position as the third most abundant marine fish in the nation’s aquaculture landscape. Nevertheless, the Japanese seabass farming grapples with significant challenges, such as the rising costs of fishmeal, the environmental consequences of intensive farming practices that contribute to water eutrophication, and an overreliance on fresh frozen bait. These challenges necessitate the urgent development of efficient, environmentally sustainable compound feeds to facilitate a shift towards sustainability and greener practices. This article provides a systematic review on the research progress in the nutritional requirements of Japanese seabass, covering protein, amino acids, lipid, essential fatty acids, carbohydrate, vitamins, and minerals. Additionally, it scrutinizes the factors affecting the precise nutritional requirements of Japanese seabass, in order to provide scientific basis for the study of precise nutritional requirements and development of efficient compound feed for Japanese seabass.

Cordycepin is a kind of nucleotide derivative with multiple biological activities, which is mostly found in Cordyceps and Cordyceps militaris. Its main pharmacological effects include anti-inflammatory, antibacterial, antiviral and improving antioxidant capacity. With the increasing improvement of Cordycepin production methods, the cost of Cordycepin has been greatly reduced from extraction process to biosynthesis, which has laid a foundation for the wide application of Cordycepin in livestock and poultry production. In this paper, the source, structure, extraction and purification, synthesis, physiological function and mechanism of Cordycepin were reviewed, and its application in livestock and poultry production was emphatically discussed. The aim was to comprehensively evaluate the pharmacological effects of Cordycepin and provide theoretical guidance for the further application of Cordycepin in livestock and poultry breeding.

Alfalfa, as an important protein feed source in ruminant animal farming, has rich nutritional value and significant production benefits. However, silage alfalfa faces many challenges in practical applications, one of which is the issue of aerobic stability. Good aerobic stability can improve the shelf life and nutritional value of feed, and reduce the impact of mold on livestock health. The raw materials of alfalfa, moisture content, temperature, compaction density, microorganisms, and types and dosages of additives all significantly influence the aerobic stability of alfalfa silage. This article reviews the research progress on aerobic stability of alfalfa silage in recent years, analyzes the influencing factors, and explores improvement measures, in order to provide references for the processing, storage, and application of alfalfa silage feed.

Vitamin B₁₂ (VB₁₂) is the only B vitamin that contains a metalion, and it plays a crucial role in regulating animal health. It significantly impacts various aspects of animal physiology, including immune regulation, antioxidant capacity, growth and development, and intestinal health. This review focuses on the immune regulatory mechanisms of VB₁₂ in animals and its applications in ruminant production, aiming to provide insights into how VB₁₂ modulates animal health and to offer references for optimizing its use in animal production strategies.

Pantothenic acid (PA), also known as vitamin B₅, serves as a key precursor of coenzyme A (CoA) and acyl carrier protein (ACP), and directly or indirectly affects the growth performance and health status of animals through the regulation of physiological processes, such as energy metabolism, lipid synthesis and immune function. Although many animals are able to produce PA endogenously through the biosynthetic pathway in the gastrointestinal microbial community, factors such as feed refinement, environmental stress and nutritional metabolism imbalance often inhibit the efficiency of endogenous synthesis in intensive aquaculture systems, increasing the risk of PA deficiency, which can lead to systemic pathologies such as growth retardation, immunosuppression, and metabolic disorders. The present review revolves around the research on the regulatory mechanisms of PA in animals and its application in animal production, aiming to gain insights into how PA regulates the health of animal organisms and to provide references for the application of PA in animal production.

Lignocellulose, the primary component of plant cell walls, is the most abundant and renewable biomass resource on earth. Its rich polysaccharide content holds tremendous potential for the development of livestock feed resources. However, the intricate and recalcitrant structure of lignocellulose limits its digestibility and utilization by livestock. Biological degradation of lignocellulose using microorganisms and their secreted enzymes offers advantages including low energy consumption, minimal pollution, and high environmental compatibility. By employing artificial intelligence algorithms such as deep learning and machine learning, researchers can efficiently extract key features from enzyme sequences and structures while predicting their performance. These approaches can effectively address the time-consuming and labor-intensive challenges associated with traditional enzyme engineering. This review summarized recent advances in applying artificial intelligence to lignocellulase engineering for lignocellulose biodegradation, aiming to provide insights for the development of lignocellulose-based feed resources and sustainable green manufacturing.

This experiment was conducted to investigate the effects of dietary Saccharomyces cerevisiae boulardii and plant polyphenols on reproductive performance, antioxidant capacity, immune function and fecal microbiota of sows. Using a 2×2 factor experimental design, 112 binary (Large White×Landrace) multiparous sows were selected and randomly divided into 4 groups according to the principle of consistent parity (2 to 4 parities) and body weight [(245±10) kg], with 28 replicates in each group and 1 sow in each replicate. Sows in the control group (CON group) were fed a basal diet, while those in the experimental groups were fed the basal diets supplemented with 0.1 g/kg Saccharomyces cerevisiae boulardii (SY group), 0.2 g/kg plant polyphenols (PPs group), and 0.1 g/kg Saccharomyces cerevisiae boulardii+0.2 g/kg plant polyphenols (SY+PPs group), respectively. The experiment started from the first day of gestation of sows and ended when the piglets were weaned. The results showed as follows: 1) dietary Saccharomyces cerevisiae boulardii and plant polyphenols had no significant effects on litter performance of sows and growth performance of suckling piglets (P>0.05). 2) Compared with CON group, dietary Saccharomyces cerevisiae boulardii significantly increased the average daily feed intake (ADFI) of sows from days 1 to 7 of lactation (P<0.05), and Saccharomyces cerevisiae boulardii and plant polyphenols had a significant interaction effect on ADFI from days 1 to 7 of lactation (P<0.05). 3) Compared with CON group, dietary plant polyphenols significantly increased the contents of immunoglobulin G and immunoglobulin M in colostrum of sows (P<0.05). 4) Compared with CON group, dietary Saccharomyces cerevisiae boulardii significantly reduced the plasma malondialdehyde (MDA) content on day of delivery and day 21 of lactation of sows (P<0.05), and significantly increased the plasma total antioxidant capacity (T-AOC) on day of delivery and the plasma glutathione peroxidase (GSH-Px) activity on day 21 of lactation (P<0.05). Dietary plant polyphenols significantly increased the plasma superoxide dismutase (SOD) activity on day of delivery, as well as the plasma T-AOC and GSH-Px activity on day 21 of lactation (P<0.05), and significantly reduced the plasma MDA content on day of delivery (P<0.05). Saccharomyces cerevisiae boulardii and plant polyphenols had significant interaction effects on plasma MDA content, T-AOC and SOD activity on day of delivery, and plasma GSH-Px activity on day 21 of lactation (P<0.05). 5) Compared with CON group, dietary Saccharomyces cerevisiae boulardii significantly reduced the contents of plasma interleukin-8 (IL-8) and tumor necrosis factor-α (TNF-α) of sows on day of delivery (P<0.05). Dietary plant polyphenols significantly reduced the contents of plasma interleukin-1β (IL-1β) and IL-8 (P<0.05). Saccharomyces cerevisiae boulardii and plant polyphenols had significant interaction effects on the contents of plasma IL-1β and TNF-α (P<0.05). 6) Compared with CON group, dietary Saccharomyces cerevisiae boulardii significantly increased the contents of acetic acid and total short-chain fatty acids in feces of sows on day of delivery (P<0.05); dietary plant polyphenols significantly increased the contents of acetic acid, propionic acid and total short-chain fatty acids in feces (P<0.05). 7) The Ace, Chao and Sobs indices of fecal microbiota in PPs group and SY+PPs group were significantly higher than those in SY group (P<0.05), and there was a tendency to be higher than those in CON group (P>0.05). The results of the linear discriminant analysis effect size (LEfSe) analysis showed that Lachnospiraceae_NK4A136_group and Parabacteroides were significantly enriched in PPs group, and Lactobacillus and Prevotellaceae_UCG-001 were significantly enriched in SY+PPs group. In conclusion, dietary Saccharomyces cerevisiae boulardii and plant polyphenols has no significant effects on reproductive performance of sows, but it can enhance the antioxidant capacity and immune function, improve the structure of fecal microbiota, promote the enrichment of beneficial bacteria, and increase the contents of short-chain fatty acids in feces.

This experiment was conducted to investigate the effects of dietary supplementation with calcium formate on the growth performance, nutrient digestion and absorption, and blood indices of Nuogu weaned piglets. Sixty healthy 33-day-old Nuogu weaned piglets with an average body weight of (11.0±0.5) kg were selected and randomly divided into 3 groups, with 4 replicates in each group and 5 pigs in each replicate. Piglets in the control group were fed a basal diet, while those in the antibiotic group and the calcium formate group were fed the basal diets supplemented with 200 mg/kg calcium oxytetracycline and 0.5% calcium formate, respectively. The pre-test period was 5 days and the formal test period was 28 days. The results showed as follows: 1) compared with the control group, the average daily gain (ADG) and average daily feed intake (ADFI) in the calcium formate group were significantly increased (P<0.05), the feed to gain ratio (F/G) was significantly decreased (P<0.05), and the diarrhea rate and diarrhea index showed a decreasing trend (P>0.05); compared with the antibiotic group, the ADFI in the calcium formate group was significantly increased (P<0.05), while there were no significant differences in ADG, F/G, diarrhea rate and diarrhea index (P>0.05). 2) Compared with the control group, the apparent digestibilities of dry matter, gross energy, crude protein, ether extract, calcium and total phosphorus in the calcium formate group was significantly or extremely significantly increased (P<0.05 or P<0.01); compared with the antibiotic group, there were no significant differences in the apparent digestibility of each nutrient in the calcium formate group (P>0.05). 3) Compared with the control group, the jejunal trypsin and α-amylase activities in the calcium formate group were significantly or extremely significantly increased (P<0.05 or P<0.01); compared with the antibiotic group, the jejunal α-amylase activity in the calcium formate group was significantly increased (P<0.05). 4) In the duodenum, compared with the control group, the mRNA relative expression levels of cationic amino acid transporter 1 (CAT1), solute carrier family 1 member 1 (SLC1A1), peptide transporter 1 (PEPT1), sodium-glucose cotransporter 1 (SGLT1) and apolipoprotein B (APOB) in the calcium formate group were significantly or extremely significantly increased (P<0.05 or P<0.01); compared with the antibiotic group, the mRNA relative expression levels of SLC1A1 and APOB in the calcium formate group were extremely significantly increased (P<0.01). In the jejunum, compared with the control group, the mRNA relative expression levels of SLC1A1, PEPT1 and APOB in the calcium formate group were extremely significantly increased (P<0.01); compared with the antibiotic group, the mRNA relative expression levels of PEPT1 and APOB in the calcium formate group were extremely significantly increased (P<0.01). 5) Compared with the control group, the plasma total protein content in the calcium formate group was significantly increased (P<0.05), the plasma glucose content was extremely significantly decreased (P<0.01), and the plasma total cholesterol and urea nitrogen contents were significantly decreased (P<0.05). Compared with the control group, the activities of serum glutathione peroxidase and total superoxide dismutase in the antibiotic group and the calcium formate group were extremely significantly increased (P<0.01), the content of serum interleukin-6 and the activity of aspartate aminotransferase were extremely significantly decreased (P<0.01), and the contents of serum immunoglobulin A and immunoglobulin M were significantly increased (P<0.05). In conclusion, dietary supplementation with calcium formate can enhance the antioxidant, anti-inflammatory and immune capabilities of Nuogu weaned piglets, increase the activities of intestinal digestive enzymes and the gene expression of nutrient transportation-related proteins, and improve the apparent digestibilities of nutrients, promoting the digestion and absorption of nutrients by the body. At the same time, it can relieve diarrhea, thereby improving their growth performance, and the effect is comparable to or better than that of antibiotics.

The aim of this experiment was to investigate the effects of dietary neutral detergent fiber (NDF) level based on a combination of fermented sauce lees and grain lees syrups on the growth performance, carcass traits and serum indexes of finishing pigs. A total of 120 three-way crossbred (Duroc×Long White×Large White) healthy growing and finishing pigs with an average weight of about 56 kg were selected and randomly divided into three groups, they were control group (CON group), test group I (F1 group) and test group II (F2 group). Each group was set up with four replicates with 10 pigs each replicate. The trial period lasted for 90 days, consisting of a 7-day preliminary period and an 83-day formal trial period. The formal trial was divided into two phases: the early fattening period (55 to 100 kg stage) lasting 52 days and the late fattening period (100 to 125 kg stage) lasting 31 days. Under the condition of keeping the same net energy and protein levels, the dietary neutral detergent fiber (NDF) levels were adjusted by incorporating fermented sauce lees and grain lees syrups. During the early fattening period, the dietary NDF levels for the three groups were set at 14% (CON group), 15% (F1 group) and 16% (F2 group), respectively. During the late fattening period, the dietary NDF levels for the three groups were set at 16% (CON group), 17% (F1 group) and 18% (F2 group), respectively. The results showed as follows: 1) during the early fattening period, compared with the CON group, both the F1 and F2 groups exhibited an extremely significant increase in final body weight and average daily gain (P<0.01), along with extremely significant decrease in feed-to-gain ratio (P<0.01). During the late fattening period, no significant difference in weight gain rate was observed between the CON group and the F1, F2 groups (P>0.05). During the full fattening period, final body weight in both F1 and F2 groups and average daily gain in the F1 group were significantly higher than those in the CON group (P<0.05), while feed-to-gain ratio was significantly lower than that in the CON group (P<0.05). 2) Compared with the CON group, the F2 group showed a significantly lower dressing percentage (P<0.05), while both F1 and F2 groups demonstrated an extremely significant increase in eye muscle area (P<0.01). 3) During the early fattening period, compared with the CON group, serum immunoglobulin A (IgA) content in the F1 group were extremely significantly increased (P<0.01), while serum immunoglobulin G (IgG) and immunoglobulin M (IgM) contents in the F2 group were extremely significantly decreased (P<0.01). During the late fattening period, compared with the CON group, serum IgG content in the F2 group was extremely significantly reduced (P<0.01). 4) During the early fattening period, compared with the CON group, serum catalase (CAT) activity in the F1 group and serum superoxide dismutase (SOD) activity in the F2 group were significantly increased (P<0.05), meanwhile, serum malondialdehyde (MDA) content in the F2 group was extremely significantly elevated (P<0.01). During the late fattening period, compared with the CON group, serum total antioxidant capacity (T-AOC) in the F1 group and serum CAT activity in the F2 group were extremely significantly enhanced (P<0.01), while serum SOD and glutathione peroxidase (GSH-Px) activities in the F2 group were extremely significantly decreased (P<0.01). 5) During the early fattening period, compared with the CON group, serum interleukin (IL)-1β and IL-2 contents in the F1 group, as well as serum IL-1β, IL-2, IL-6, tumor necrosis factor-α (TNF-α) and transforming growth factor-β (TGF-β) contents in the F2 group were extremely significantly reduced (P<0.01), serum IL-4 content in both F1 and F2 groups was extremely significantly increased (P<0.01), while serum IL-10 content in the F2 group was significantly elevated (P<0.05). During the late fattening period, compared with the CON group, serum IL-1β and TGF-β contents in the F1 group, as well as serum IL-1β, IL-6, TNF-α and TGF-β contents in the F2 group, were extremely significantly decreased (P<0.01), meanwhile, serum IL-4 content in both F1 and F2 groups was extremely significantly elevated (P<0.01). In conclusion, under this experimental condition, based on a combination of fermented sauce lees and grain lees syrups to elevate dietary NDF level in diets can improve the growth performance and carcass traits, and regulate the contents of serum inflammatory factors of finishing pigs. Overall, the best effect is achieved when the dietary NDF level is 15% in the early fattening period and 17% in the late fattening period.

This experiment was conducted to study the effects of dietary different supplemental levels of fermented feed on laying performance, intestinal morphology, digesta digestive enzyme activities and cecal microbiota of laying hens. A total of 360 Hy-Line brown laying hens at 40 weeks of age were randomly divided into 3 groups with 8 replicates per group and 15 hens per replicates. Hens in the control group were fed a corn-soybean meal basal diet, and others in experimental groups were fed experimental diets containing 5% and 10% fermented feed, respectively. The experiment lasted for 12 weeks. The results showed as follows: 1) there were no significant differences in laying rate, average egg weight, daily average egg weight, average daily feed intake and feed to egg ratio among all groups (P>0.05). 2) The gizzard weight of 5% and 10% fermented feed groups was significantly lower than that of the control group (P<0.05), and the gizzard relative weight of 10% fermented feed group was significantly lower than that of the control group (P<0.05). 3) The villus height in jejunum of 5% fermented feed group and the villus height and villus height/crypt depth ratio in jejunum of 10% fermented feed group were significantly higher than those in control group (P<0.05). 4) The jejunal digesta lipase activity of 5% and 10% fermented feed groups was significantly higher than that in control group (P<0.05). 5) The Observed species index and Shannon index of cecal microbiota of 10% fermented feed group were significantly higher than those of the control group (P<0.01). At the phyla level, the relative abundances of Proteobacteria and Verrucomicrobiota in cecum of 10% fermented feed group were significantly higher than those of the control group (P<0.01), the relative abundance of Actinobacteriota in cecum was significantly lower than that of the control group (P<0.01), and the relative abundances of Synergistota and Verrucomicrobiota in cecum were significantly higher than those of 5% fermented feed group (P<0.05). 6) The microbial groups that played an important role in 5% fermented feed group were concentrated in the Ruminococcaceae, and in the 10% fermented feed group were concentrated in the Akkermansiaceae. In conclusion, the use of fermented feed in the diet can improve the jejunal morphology of laying hens, enhance the jejunal digestive enzyme activity, and increase the species richness, diversity index and beneficial microorganisms’ numbers. Comprehensive analysis, it is recommended to use fermented feed at a level of 10% in diet for laying hens after the laying peak period.

The aim of this experiment was to investigate the effects of yeast culture on performance, egg quality, immune function and cecal microflora of laying hens. A total of 288 sixty-five-week-old Hy-Line brown laying hens were randomly divided into 4 groups with 6 replicates per group and 12 hens per replicate. The control group (NC group) was fed a basal diet, and the experimental groups were fed the basal diet supplemented with 0.3% (T1 group), 0.5% (T2 group) and 0.8% (T3 group) yeast culture, respectively. The experiment lasted for 8 weeks. The results showed as follows: 1) compared with the NC group, the laying rate of T1 group and T2 group was significantly increased (P<0.05). 2) Compared with the NC group, the egg Haugh unit of T1 group was significantly increased (P<0.05). 3) Compared with the NC group, the serum immunoglobulin G content of T2 group and T3 group was significantly increased (P<0.05). 4) Compared with the NC group, at the phylum level, the relative abundance of Desulfobacterota in cecum of T2 group was significantly decreased (P<0.05); at the genus level, the relative abundance of Lactobacillus in cecum of T2 group was significantly increased (P<0.05), and the relative abundance of Desulfovibrio in cecum was significantly decreased (P<0.05). In summary, dietary yeast culture can increase the laying rate of laying hens, improve egg quality, enhance immune function, and improve the cecal microbial community structure. Under this experimental condition, the appropriate supplemental level of yeast culture for laying hens is 0.5%.

The aim of this study was to investigate the effects of dietary docosahexaenoic acid (DHA) on performance, egg quality and liver function of laying hens with fatty liver hemorrhage syndrome (FLHS) during late laying period. A total of 240 Hy-Line Brown laying hens at 71 weeks of age were randomly assigned to 3 groups with 8 replicates per group and 10 hens per replicate. The control group was fed a basal diet, the high-energy and low-protein group (HELD group) was fed a high-energy and low-protein diet (the basal diet supplemented with 5% chicken oil), and the DHA group was fed a high-energy and low-protein diet containing DHA (replaced 1% soybean oil with 1% DHA in the high-energy and low-protein diet). The experiment period was 12 weeks. The results showed as follows: 1) compared with the control group, the laying rate and average daily feed intake of the HELD group were significantly decreased (P<0.05). Compared with the HELD group, the laying rate of the DHA group was significantly increased (P<0.05). 2) Compared with the control group, the eggshell yellowness (b^*) value, eggshell strength, eggshell weight and eggshell thickness on week 8 and the eggshell thickness on week 12 of the HELD group were significantly decreased (P<0.05). Compared with the HELD group, the eggshell strength, eggshell weight, and eggshell thickness on week 8 and the eggshell thickness on week 12 of the DHA group were significantly increased (P<0.05). 3) Compared with the control group, the liver weight, liver color, abdominal fat weight and abdominal fat index of the HELD group were significantly increased (P<0.05). Compared with the HELD group, the pancreatic weight and pancreatic index of the DHA group were significantly decreased (P<0.05). 4) Compared with the HELD group, the big yellow follicle number of the DHA group was significantly increased (P<0.05), and the genital tract length was significantly decreased (P<0.05). 5) Compared with the control group, the contents of triglycerides (TG) and total cholesterol (TC) in liver of the HELD group were significantly increased (P<0.05). Compared with the HELD group, the liver TC content of the DHA group was significantly decreased (P<0.05). In conclusion, dietary DHA can mitigate the decline in laying rate induced by FLHS, enhance the egg quality, and alleviate the adverse effects of FLHS on the performance of laying hens.

This experiment was conducted to investigate the effects of dietary Schizochytrium powder on growth performance, meat quality, organ development, serum biochemical indexes, oxidative stress and inflammatory response of yellow-feathered broilers under heat stress. A total of 144 male fast yellow-feathered broilers aged at 35 days were randomly divided into 3 groups with 6 replicates in each group and 8 broilers in each replicate. Broilers in the control group (CON group) and heat stress group (HS group) were fed a basal diet, and others in the Schizochytrium powder group (SP group) were fed the basal diet supplemented with 20 g/kg Schizochytrium powder. The pre-experimental period lasted for 1 week, and the experimental period lasted for 2 weeks. After the pre-experimental period, the CON group maintained normal temperature, and HS group and SP group were treated with cyclic heat stress. The results showed that compared with the CON group, the final body weight, average daily gain, average daily feed intake, breast muscle water-holding capacity, liver index and spleen index of HS group were significantly decreased (P<0.05), the feed to gain ratio was significantly increased (P<0.05), the serum aspartate aminotransferase (AST) activity and glucose (GLU), high density lipoprotein cholesterol (HDL-C) and low density lipoprotein cholesterol (LDL-C) contents were significantly increased (P<0.05), the serum and liver superoxide dismutase (SOD) activity was significantly increased (P<0.05), the jejunum villus height/crypt depth was significantly increased (P<0.05), and the mRNA relative expression levels of NOD-like receptor thermal protein domain associated protein 3 (NLRP3) and interleukin-6 (IL-6) in liver were significantly increased (P<0.05). Compared with the HS group, the breast muscle water-holding capacity, liver index and serum, liver and jejunum malondialdehyde (MDA) content of SP group were significantly increased (P<0.05), the bursa of Fabricius index was significantly decreased (P<0.05), the serum total cholesterol (TC) and HDL-C contents and catalase (CAT) activity were significantly decreased (P<0.05), and the mRNA relative expression level of NLRP3 in liver was significantly decreased (P<0.05). In conclusion, dietary Schizochytrium powder can improve the meat quality of yellow-feathered broilers, alleviate the liver damage and inflammatory reaction caused by heat stress, improve the lipid metabolism ability, and aggravate the oxidative damage of serum, liver and jejunum under heat stress.

This experiment was conducted to investigate the temperature tolerance of thermostable acid protease (TAP), degradation characteristics of soybean meal antigen protein, and the effects of its supplementation in low protein corn-soybean meal type diet on growth performance and nutrient apparent metabolic rates of yellow feathered chickens. In vitro experiment was conducted to determine the temperature tolerance of TAP by water bath method and granulation method. The degradation effects of different addition amounts of TAP [0 (blank), 2, 4, 6 and 8 U/g] on antigen protein in soybean meal raw materials were analyzed. Meanwhile, the effects of TAP on the protein digestibility in corn-soybean meal type diet were determined through bionic digestion experiment. In vivo, 480 healthy one-day-old fast-growing yellow feathered male chickens were selected and randomly divided into 6 groups with 8 replicates in each group and 10 chickens in each replicate. Chickens in the normal protein group were fed a normal protein level corn-soybean meal type basal diet, those in the low protein group were fed a low protein level corn-soybean meal type diet, and those in experimental groups 1 to 4 were fed the diets supplemented with 2, 4, 6 and 8 U/g TAP on the basis of the low protein group diet, respectively. The experiment lasted for 56 days. The results showed as follows: 1) TAP still retained a relatively high activity (retention rate of 80.00%) under the granulation condition of 80 ℃ and had strong temperature tolerance. 2) Compared with the soybean meal raw materials and the blank group, the supplementation of different doses of TAP significantly increased the acid-soluble protein (ASP) content (P<0.05), and the supplementation of 4 to 8 U/g TAP significantly decreased the contents of glycinin and β-conglycinin (P<0.05). 3) In the bionic digestion experiment, compared with the blank group, the supplementation of 4 to 8 U/g TAP significantly increased the digestibilities of dry matter (DM) and crude protein (CP) (P<0.05). 4) From 1 to 21 days of age, compared with the normal protein group, the average daily feed intake (ADFI) and feed to gain ratio (F/G) in the experimental groups were significantly increased (P<0.05); compared with the low protein group, the ADFI in experimental groups 1 and 2 was significantly increased (P<0.05). From 22 to 42 days of age, compared with the normal protein group and the low protein group, the F/G in experimental group 2 was significantly decreased (P<0.05). From 43 to 56 days of age, compared with the normal protein group and the low protein group, there was a decreasing trend of F/G in experimental groups 2 to 4 (P=0.068). 5) Compared with the normal protein group, the apparent metabolic rates of DM, CP and gross energy (GE) in the experimental groups were significantly increased (P<0.05), and the apparent metabolic rate of phosphorus in experimental group 4 was significantly increased (P<0.05). Compared with the low protein group, the apparent metabolic rates of DM, CP and GE in experimental group 4 were significantly increased (P<0.05), and the apparent metabolic rate of calcium in experimental groups 2 to 4 was significantly increased (P<0.05). To sum up, TAP has strong temperature tolerance, which can increase the ASP content in soybean meal and reduce the antigen protein content. The supplementation of 4 to 8 U/g TAP in low protein diet of yellow feathered chickens can increase the nutrient apparent metabolic rates and improve their growth performance.

This experiment aimed to investigate the effects of dietary Streptococcus alactolyticus from chickens on growth performance, meat quality, antioxidant capacity and expression of inflammatory factors in muscle of white-feathered broiler chickens. The Streptococcus alactolyticus FM231008 used in the experiment was screened out from broiler chicken feces by our laboratory, and was identified as Streptococcus alactolyticus with the sequence compared with the NCBI database. A total of 360 one-day-old healthy Arbor Acres (AA) white-feathered broiler chickens were selected and randomly divided into 5 groups, with 6 replicates in each group and 12 chickens in each replicate. The chickens in the control group (CON group) were fed a basal diet, while those in the experimental groups were fed the basal diets supplemented with 2.5×10¹⁰ (T1 group), 5.0×10¹⁰ (T2 group), 7.5×10¹⁰ (T3 group) and 10.0×10¹⁰ CFU/kg (T4 group) Streptococcus alactolyticus powder, respectively. The experiment lasted for 42 days. The results showed as follows: 1) there were no significant differences in growth performance and slaughter performance among all groups (P>0.05). 2) Compared with CON group, the pH_{45 min} in breast muscle in T3 group was significantly decreased (P<0.05), the pH_{24 h} and water loss rate in breast muscle in T3 and T4 groups were significantly decreased (P<0.05), the redness (a^*) and yellowness (b^*) values in breast muscle in T1 and T2 groups were significantly decreased (P<0.05), and the shear force in breast muscle in each experimental group was significantly decreased (P<0.05). 3) At 21 days of age, compared with CON group, the activities of total superoxide dismutase (T-SOD) and catalase (CAT) in serum in T1 and T4 groups were significantly increased (P<0.05), and the malondialdehyde (MDA) content in serum was significantly decreased (P<0.05); the glutathione peroxidase (GSH-Px) activity in serum in T1 group was significantly increased (P<0.05); the CAT activity in serum in T2 group was significantly increased (P<0.05); the MDA content in serum in T3 group was significantly decreased (P<0.05). Compared with CON group, the MDA content in breast muscle in each experimental group was significantly decreased (P<0.05), and the total antioxidant capacity (T-AOC) in breast muscle in T2 and T4 groups was significantly increased (P<0.05). At 42 days of age, compared with CON group, the CAT activity in serum in each experimental group was significantly increased (P<0.05); the T-AOC in serum in T1 and T4 groups was significantly increased (P<0.05); the GSH-Px activity in serum in T2, T3 and T4 groups was significantly increased (P<0.05), and the MDA content in serum was significantly decreased (P<0.05); the T-SOD activity in serum in T3 group was significantly increased (P<0.05). Compared with CON group, the MDA content in breast muscle in T1, T3 and T4 groups was significantly decreased (P<0.05), and the T-AOC in breast muscle in T2 group was significantly increased (P<0.05). 4) At 21 days of age, compared with CON group, the mRNA relative expression levels of interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in breast muscle in each experimental group were significantly decreased (P<0.05), the interleukin-2 (IL-2) mRNA relative expression level in breast muscle in T1, T3 and T4 groups was significantly decreased (P<0.05), and the interleukin-10 (IL-10) mRNA relative expression level in breast muscle in T1 and T3 groups was significantly decreased (P<0.05). At 42 days of age, compared with CON group, the mRNA relative expression levels of IL-1β, IL-6 and TNF-α in breast muscle in each experimental group were significantly decreased (P<0.05), the IL-2 mRNA relative expression level in breast muscle in T2 group was significantly decreased (P<0.05), and the IL-10 mRNA relative expression level in breast muscle in T2 and T3 groups was significantly decreased (P<0.05). In conclusion, under the conditions of this experiment, appropriate dose of dietary Streptococcus alactolyticus from chickens can improve the meat quality and alleviate oxidative stress by enhancing antioxidant capacity and regulating inflammatory responses of white-feathered broiler chickens.

This experiment aimed to investigate the effects of adding different doses of copper in the forms of copper sulfate (CS) and coated copper sulfate (CCS) to the diet on the growth performance, copper deposition in tissues and ileal microbiota of broilers. A total of 480 one-day-old male Ross 308 broilers were selected and randomly divided into 4 groups, with 6 replicates in each group and 20 broilers in each replicate. The experiment adopted a 2×2 factorial design. The two factors were the form of copper addition (CS and CCS) and the dose of copper addition (3.90 and 5.85 mg/kg). According to the experimental design, different forms and doses of copper were added to the basal diet, respectively: group Ⅰ, 3.90 mg/kg of copper was added in the form of CS; group Ⅱ, 3.90 mg/kg copper was added in the form of CCS; group Ⅲ, 5.85 mg/kg copper was added in the form of CS; group Ⅳ 5.85 mg/kg copper was added in the form of CCS. The pre-test period was from 1 to 7 days of age, and the formal test period was from 8 to 49 days of age. The formal test period was divided into two stages: 8 to 28 days of age and 29 to 49 days of age. The results showed that compared with CS, CCS could significantly increase the average daily gain (ADG) of broilers at the 8 to 28 days of age and 8 to 49 days of age (P<0.05), and extremely significantly reduce the average daily feed intake (ADFI) of broilers at the 29 to 49 days of age (P<0.01), as well as the ADFI and feed/gain ratio (F/G) of broilers at the 8 to 49 days of age (P<0.01). The addition dose of copper had no significant effect on the growth performance of broilers (P>0.05). In terms of copper deposition in tissues, compared with CS, CCS could extremely significantly increase the copper content in the liver of broilers (P<0.01). The copper content in the liver of broilers in group Ⅳ was extremely significantly higher than that in groups Ⅰ and Ⅲ (P<0.01), there was no significant difference compared with group Ⅱ (P>0.05). In terms of ileal microbiota, compared with CS, CCS could significantly increase the Simpson index of ileal microbiota of broilers (P<0.05); adding 3.90 mg/kg copper could significantly increase the Simpson index of ileal microbiota compared with adding 5.85 mg/kg copper (P<0.05). The Simpson index of group Ⅲ was significantly lower than that of groups Ⅰ, Ⅱ and Ⅳ (P<0.05). Based on a comprehensive assessment of various indicators, it is concluded that adding 3.90 mg/kg copper in the form of CCS to the diet of broilers can achieve better results.

The purpose of this experiment was to study the effects of dietary soluble fiber (SF) level on growth performance, serum indexes and intestinal development of 28 to 70 day-old-geese. A total of 300 healthy 28-day-old Wugang Tong geese with similar weight were randomly divided into 5 groups with 6 replicates in each group and 10 geese (male and female each account for 1/2) in each replicate. The dietary SF levels in each group were 10.05% (control), 10.53%, 11.00%, 11.49% and 11.95%, respectively. The trial period was 42 days. The results showed as follows: 1) the dietary SF level had no significant effect on the average daily gain (ADG), average daily feed intake (ADFI), feed-to-weight ratio (F/G) and wing inversion rate of 28 to 70-day-old geese (P>0.05). 2) The dietary SF level had a significant effect on serum antioxidant indexes of 70-day-old geese (P<0.05). The serum malondialdehyde (MDA) content in 10.05%SF group was significantly higher than that in other groups (P<0.05), and the total antioxidant capacity (T-AOC) was significantly lower than that in other groups (P<0.05). The activity of catalase (CAT) in serum in 11.49%SF group was significantly higher than that in 10.05%SF, 10.53%SF and 11.00%SF groups (P<0.05). The serum total superoxide dismutase (T-SOD) activity in 11.00%SF, 11.49%SF and 11.95%SF groups was significantly higher than that in 10.05%SF and 10.53%SF groups (P<0.05). Serum glutathione peroxidase (GSH-Px) activity in 11.49%SF group was significantly higher than that in other groups (P<0.05). There was no significant interaction effect between the dietary SF level and the gender of 70-day-old meat geese on the serum antioxidant indexes (P>0.05). 3) The level of SF had a significant effect on the serum total protein (TP)content (P<0.05). Compared with the 10.05%SF group, the serum TP content in the 11.95%SF group decreased significantly (P<0.05), however, it had no significant effect on other serum biochemical indexes (P>0.05). There was no significant interaction effect between the dietary SF level and the gender of 70-day-old geese on serum biochemical indexes (P>0.05). 4) Dietary SF level had no significant effect on the relative length and weight of each intestinal segment of goose (P>0.05). There were significant differences in the relative length of duodenum, jejunum and ileum and the relative weight of jejunum and ileum between male and female geese (P<0.05), and the female goose was significantly larger than the male geese (P<0.05). There was a significant interaction effect between dietary SF level and gender of 70-day-old geese on the relative length of jejunum (P<0.05), but there was no significant interaction effect on the relative length and weight of other intestinal segments (P>0.05). 5) Dietary SF level had significant effects on jejunum and ileum morphology of geese (P<0.05). The jejunal villus height and villus height/crypt depth (V/C) in 10.53%SF, 11.00%SF and 11.49%SF groups were significantly higher than those in 10.05%SF and 11.95%SF groups (P<0.05). The jejunal crypt depth in 11.49%SF group was significantly lower than that in 10.05%SF, 10.53%SF and 11.00%SF groups (P<0.05). The height and V/C of ileal villus in 11.49%SF and 11.95%SF groups were significantly higher than those in 10.05%SF and 10.53%SF groups (P<0.05), and the depth of ileal crypt in 11.49%SF and 11.95%SF groups was significantly lower than that in 10.05%SF and 10.53%SF groups (P<0.05). There were significant differences in ileal crypt depth and V/C between male and female geese (P<0.05). The depth of ileal crypt in female geese was significantly higher than that in male geese (P<0.05), but V/C was significantly lower than that in male geese (P<0.05). There was a significant interaction effect between dietary SF level and gender of 70-day-old geese on jejunum villus height and V/C, and ileum villus height (P<0.05), but there was no significant interaction effect on other morphological parameters (P>0.05). 6) Dietary SF level had a significant effect on propionic acid content in cecal chyme of 70-day-old geese (P<0.05), and the content of propionic acid in 10.05%SF group was significantly lower than that in other groups (P<0.05). There was no significant interaction effect between dietary SF level and gender of 70-day-old geese on cecal digesta volatile fatty acid content (P>0.05). In conclusion, dietary SF supplemented with 11.49% can significantly improve the antioxidant performance of 70-day-old Wugang Tong geese and has a positive effect on the healthy development of intestinal tract without adverse effects on growth performance. Therefore, in this study, 11.49% of dietary SF is recommended as an adaptive addition level for Wugang Tong geese aged 28 to 70 days.

This experiment was conducted to study the effects of different levels of dietary stored wheat (SW) on growth performance and small intestinal immune performance in 22 to 42-day-old goslings. After feeding the male chicks to 21 days of age, 432 one-day-old experimental geese with uniform body weight and close to (1 027.83±0.41) g were selected and randomly divided into 6 groups with 6 replicates per group and 12 geese per replicate. The proportion of SW replacing maize in diets of each group was 0, 20%, 40%, 60%, 80% and 100%, respectively. The corresponding dietary SW levels were 0 (SW0 group), 12.4% (SW12 group), 24.8% (SW25 group), 37.2% (SW37 group), 49.6% (SW50 group) and 62.0% (SW62 group). The experiment lasted for 21 days. The results showed as follows: 1) compared with the SW0 group, dietary SW inclusion had no significant effect on body weight gain (BWG) (P>0.05). However, BWG in SW50 and SW62 groups was significantly lower than that in SW12 and SW37 groups (P<0.05). 2) Compared with SW0 group, the contents of diamine oxidase, endotoxin and D-lactic acid in the serum of other experimental groups were significantly or extremely significantly increased (P<0.05 or P<0.01). The relative expression of zonula occludens-1 gene in SW37 group was significantly increased (P<0.05), and the relative expression of Occludin gene was significantly increased (P<0.05). The relative expression of tight junction protein-2 gene in SW50 group was extremely significantly decreased (P<0.01). 3) With the increase of dietary SW level, the contents of immunoglobulin A, immunoglobulin G and immunoglobulin M in intestinal mucosa increased extremely significantly (P<0.01). Compared with the SW0 group, the contents of interleukin-1β and interleukin-2 in the intestinal mucosa of the other experimental groups were significantly or extremely significantly increased (P<0.05 or P<0.01), and the content of interleukin-10 in the SW37 group was extremely significantly decreased (P<0.01). The relative gene expression of interleukin-2 in the intestinal mucosa of the SW37 group was significantly increased (P<0.05). 4) Compared with the SW0 group, the glutathione content and superoxide dismutase activity in the intestinal mucosa of the other experimental groups were extremely significantly decreased (P<0.01), and the malondialdehyde content was significantly or extremely significantly increased (P<0.05 or P<0.01). In conclusion, in the absence of enzyme preparation, excessive replacement of maize by SW in the early feeding period (22 to 42 days of age) may cause the increase of intestinal permeability, the decrease of intestinal immune function and antioxidant performance, destroy the stability of intestinal barrier, and lead to the decline of growth performance of offspring geese. In production, it is recommended that the level of SW in the diet of geese aged 22 to 42 days should not exceed 37%, and the level of SW in the diet of geese can be further reduced to ensure the healthy growth of geese.

This experiment aimed to investigate the effects of Mongolian herbal mineral lick block on serum biochemical, antioxidant, immune indices and mineral content of dairy cows. Thirty Holstein dairy cows in mid-lactation with good body condition, similar body weight [(615.0±41.6) kg], milk yield [(30.56±2.18) kg] and parity (2 to 3 parities) were selected and randomly divided into 2 groups, with 15 cows in each group. Cows in the control group were supplemented with ordinary mineral lick block, while others in the test group were supplemented with Mongolian herbal mineral lick block, with both lick blocks containing the same mineral element content. The pre-trial period lasted 7 days, and the formal trial period lasted 42 days. The results showed as follows: 1) on day 21, compared with the control group, the serum urea nitrogen (UN) and total cholesterol (TC) contents of dairy cows in the test group were significantly increased (P<0.05); on day 42, compared with the control group, the serum glucose (GLU), UN and TC contents of dairy cows in the test group were significantly increased (P<0.05), while the serum albumin (ALB) content was significantly decreased (P<0.05). 2) On day 21, compared with the control group, the serum total antioxidant capacity (T-AOC) and activities of superoxide dismutase (SOD) and catalase (CAT) of dairy cows in the test group were significantly increased (P<0.05), while the serum malondialdehyde (MDA) content was significantly decreased (P<0.05). On day 42, compared with the control group, the serum T-AOC and activities of SOD, CAT and glutathione peroxidase (GSH-Px) of dairy cows in the test group were significantly increased (P<0.05), and the serum MDA content was significantly decreased (P<0.05). 3) On day 21, compared with the control group, the serum immunoglobulin G (IgG) and immunoglobulin M (IgM) contents of dairy cows in the test group were significantly increased (P<0.05), while the serum interleukin-6 (IL-6) content was significantly decreased (P<0.05). On day 42, compared with the control group, the serum immunoglobulin A (IgA), IgG and IgM contents of dairy cows in the test group were significantly increased (P<0.05), and the serum IL-6 and tumor necrosis factor-α (TNF-α) contents were significantly decreased (P<0.05). 4) Compared with the control group, the serum contents of calcium, phosphorus, magnesium, sodium, copper, iron, zinc, manganese and selenium of dairy cows in the test group showed no significant changes (P>0.05). In conclusion, supplementing with Mongolian herbal mineral lick block can improve the antioxidant capacity and immune function of dairy cows without significantly affecting serum mineral contents.

The aim of this experiment was to investigate the effects of subacute rumen acidosis (SARA) on lactation performance, nutrient apparent digestibility and serum biochemical, antioxidant and immune indexes of dairy cows. The 16 Holstein cows with similar body condition, parity, body weight, lactation days and milk yield were divided into 2 groups, named CON group and SARA group, with 8 cows in each group. Cows in the CON group were fed a basal diet with a concentrate to forage ratio of 5∶5, cows in the SARA group were supplemented with 1 kg/d pressed corn based on CON group, and the ratio of dietary concentrate to forage was 6∶4. The experimental period includes a 15-day pre-feeding period and a 45-day formal trial period. The results showed as follows: 1) compared with the control group, the contents of propionic acid, butyric acid, total volatile fatty acid and lactic acid in the rumen of cows in SARA group were significantly or extremely significantly increased (P<0.05 or P<0.01), while the content of acetic acid and rumen pH were significantly decreased (P<0.05). In SARA group, milk fat percentage was extremely significantly decreased on days 15, 30, and 45 (P<0.01), body cell number was extremely significantly increased on day 15 (P<0.01), milk yield was decreased from days 1 to 45 (P>0.05), and energy-corrected milk yield was extremely significantly decreased (P<0.01). The apparent digestibility of dry matter (DM), organic matter (OM) and acid detergent fiber (ADF) decreased significantly or extremely significantly (P<0.05 or P<0.01). 2) On days 15 and 45, the serum albumin (ALB) content of cows in SARA group was significantly higher than that in control group (P<0.05). On days 15 and 45, serum catalase (CAT) activities in SARA group were significantly lower than those in control group (P<0.05), while serum malondialdehyde (MDA) content was significantly higher (P<0.05). On day 45, compared with the control group, the activities of serum peroxidase (POD), glutathione peroxidase (GSH-Px) and lysozyme (LZM) in SARA group were extremely significantly decreased (P<0.01), and the total antioxidant capacity (T-AOC) was significantly decreased (P<0.05). On days 15 and 45, the serum contents of interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and amyloid protein (SAA) in SARA group were significantly or extremely significantly higher than those in control group (P<0.05 or P<0.01). The content of serum immunoglobulin A (IgA) on day 45 decreased significantly (P<0.05), while the content of haptoglobin (HP) increased significantly (P<0.05). In summary, SARA can change rumen fermentation mode, cause oxidative stress, inflammatory response and decrease immune capacity of dairy cows, and lead to a decline in lactation performance and a higher risk of mastitis in dairy cows.

This experiment was conducted to investigate the effects of folic acid (FA) and coated folic acid (CFA) on lactation performance, rumen fermentation and hepatic FA metabolism in transition dairy cows. Eighty transition dairy cows with similar parity [(2.03±0.18) parities], body weight [(676.0±33.6) kg], milk production in the previous lactation period [(10 155.0±256.2) kg] and expected delivery date were assigned in a randomized block design into 4 groups with 20 cows in each group. Cows in the control group (CON group) were fed a basal diet, while those in the experimental groups were fed the basal diets supplemented with 6.75 g/d CFA (contained 2% FA, CFA group), 135 mg/d FA (LFA group) and 270 mg/d FA (HFA group), respectively. The experiment began from 35 days before calving, and the data and sample collection period was from 0 to 21 days after calving. The results showed as follows: 1) the milk yield, 4% fat-corrected milk yield, milk protein yield and feed efficiency in CFA group were significantly higher than those in CON group, LFA group and HFA group (P<0.05), and the milk fat yield was significantly higher than that in CON group and LFA group (P<0.05). 2) Compared with CON group, the rumen FA content, the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and the total volatile fatty acid (TVFA) content in CFA group, LFA group and HFA group were significantly increased (P<0.05), while the rumen malondialdehyde (MDA) content was significantly decreased (P<0.05). Meanwhile, compared with CFA group, the activities of rumen SOD and GSH-Px and the TVFA content in LFA group and HFA group were significantly increased (P<0.05), while the rumen MDA content and the acetate to propionate ratio were significantly decreased (P<0.05). 3) There was no significant difference in the rumen microbiota α diversity indices among the groups (P>0.05). At the phylum level, the rumen Bacteroides relative abundance in LFA group was significantly higher than that in the other groups (P<0.05), while the rumen Firmicutes relative abundance was significantly lower than that in the other groups (P<0.05). At the genus level, the relative abundances of rumen uncultured_rumen_bacterium and Prevotellaceae_UCG-001 in LFA group was significantly higher than those in the other groups (P<0.05), the rumen Rikenellaceae_RC9_gut_group relative abundance in CFA group, LFA group and HFA group was significantly higher than that in CON group (P<0.05), and the rumen Ruminococcaceae_UCG-014 relative abundance in CFA group was significantly higher than that in the other groups (P<0.05). 4) The hepatic FA content and the mRNA relative expression levels of dihydrofolate reductase (DHFR) and 5,10-methylenetetrahydrofolate reductase (MTHFR) in CFA group were significantly higher than those in the other groups (P<0.05), while the hepatic homocysteine content was significantly lower than that in the other groups (P<0.05). In conclusion, the supplementation of CFA can enhance the lactation performance in dairy cows, which is related to the improvement of rumen fermentation and liver FA metabolism; the supplementation of CFA can stimulate the growth of rumen cellulolytic bacteria, and the supplementation of 135 mg/d FA can stimulate the growth of rumen amylolytic bacteria.

This experiment was conducted to investigate the effects of grape seed proanthocyanidin (GSP) on performance, milk fatty acid composition, serum indexes and rumen fermentation parameters of lactating dairy cows. Thirty-two healthy Holstein cows with similar body weight [(683±14) kg] were selected and assigned to a completely randomized block design, with parity, days in milk and initial milk yield as blocking factors. The cows were randomly divided into 2 groups, with 16 cows in each group. Cows in the control group (CON group) were fed a basal diet, while those in the GSP group were fed the basal diet supplemented with 50 g/d of GSP. The pre-test period lasted for 15 days, and the formal test period lasted for 45 days. During the experiment, milk yield was recorded daily. Rumen fluid and milk samples were collected on days 15, 30, 45 and 60, and blood samples were collected on days 21, 35 and 49. The results showed that compared with the CON group, the GSP group had significantly increased milk protein rate and the proportions of stearic acid and linoleic acid in milk fatty acids (P<0.05), while the proportions of myristoleic acid, pentadecanoic acid, palmitoleic acid and heptadecanoic acid in milk fatty acids were significantly decreased (P<0.05). The serum superoxide dismutase (SOD) activity tended to increase (P=0.065), and the serum interleukin-6 (IL-6) content tended to decrease (P=0.081). Meanwhile, the serum tumor necrosis factor-α (TNF-α) and lipopolysaccharide (LPS) contents were significantly decreased (P<0.05). The concentration of isobutyric acid in rumen fluid was significantly increased (P<0.05), while the acetate/propionate ratio in rumen fluid was significantly decreased (P<0.05). In conclusion, supplementary feeding of 50 g/d GSP can improve milk protein percentage and the proportion of polyunsaturated fatty acids in milk, thereby enhancing milk quality. It can also reduce the acetate/propionate ratio in rumen fluid to optimize rumen fermentation parameters, and decrease serum LPS, IL-6 and TNF-α contents while increasing serum SOD activity, which is beneficial to promoting the health of dairy cows.

This experiment was conducted to investigate the effects of dietary calcium salt of short-chain fatty acid and probiotics on growth performance, nutrient apparent digestibility, serum indices and rumen microbiota of Angus crossbred steers. Fifty-one healthy Angus crossbred steers with an initial body weight of (457.5±42.5) kg were selected and randomly divided into 3 groups, with 17 replicates in each group and 1 cattle in each replicate. Steers in the control group (CON group) were fed a basal diet, while those in the experimental groups were fed the basal diets supplemented with 1.5 g/kg DM Propionibacterium metabolites (calcium salt of short-chain fatty acid content≥50.0%, CMP group), and 1.5 g/kg DM Propionibacterium metabolites and probiotics (yeast and Bacillus subtilis, CMPM group), respectively. The pre-experiment lasted for 7 days and the experiment lasted for 90 days. The results showed as follows: 1) compared with CON group, the final body weight of beef cattle in CMPM group was significantly increased (P<0.05), and the average daily gain and average daily feed intake were extremely significantly increased (P<0.01). 2) Compared with CON group, the crude protein (CP) apparent digestibility of beef cattle in CMP group and CMPM group was significantly increased (P<0.05), and the neutral detergent fiber (NDF) apparent digestibility was extremely significantly increased (P<0.01). 3) Compared with CON group, the serum urea content of beef cattle in CMP group was extremely significantly decreased (P<0.01); the serum total protein content in CMPM group was significantly decreased (P<0.05), and the serum urea content in serum was extremely significantly decreased (P<0.01). 4) There were no significant differences in each index of alpha diversity of rumen microbiota of beef cattle among the groups (P>0.05). At the phylum level, compared with CON group, the relative abundances of Verrucomicrobiota and Cyanobacteria in rumen in CMP group were significantly decreased (P<0.05); at the genus level, compared with CON group, the relative abundances of Oscillospiraceae_NK4A214_group and Lachnospiraceae_NK3A20_group in rumen in CMP group was significantly increased (P<0.05), and the WCHB1-41 relative abundance in rumen was significantly decreased (P<0.05). In conclusion, dietary calcium salt of short-chain fatty acid and probiotics can increase the dry matter intake and average daily gain of Angus crossbred steers, improve the apparent digestibilities of CP and NDF, reduce the serum urea content, and increase the relative abundances of rumen fibre-degrading bacteria.

This experiment was conducted to investigate the effects of guanidino acetic acid (GAA) supplementation in diets with different protein levels on plasma hormone indices, serum biochemical indices, meat quality and antioxidant capacity of yaks (Bos grunniens), and to provide technical reference for the rational use of GAA in yak breeding. Forty-eight male yaks aged 4 to 5 years were selected and randomly divided into 6 groups with 8 replicates per group and 1 yak per replicate. Using a 2×3 two-factor experimental design, the 2 dietary protein levels were 12.88% (low) and 17.00% (high), respectively, and the 3 GAA supplemental levels were 0, 0.1%, 0.2% of the concentrate (dry matter basis), respectively. The pre-experimental period lasted for 10 days, and the experimental period lasted for 90 days. The results showed as follows: 1) the plasma insulin (INS) and insulin-like growth factor-1 (IGF-1) contents of low protein diet group were significantly lower than those of high protein diet group (P<0.05). The plasma INS content of 0.2% GAA group was significantly lower than that of 0 and 0.1% GAA groups (P<0.05). 2) The serum total antioxidant capacity (T-AOC) of low protein diet group was significantly higher than that of high protein diet group (P<0.05). 3) The pH and contents of lysine, threonine, valine, isoleucine, alanine, glutamic acid, serine and aspartic acid in Longissimus dorsi of low protein diet group were significantly higher than those of high protein diet group (P<0.05), and the contents of phenylalanine, proline, cystine, and tyrosine in Longissimus dorsi were significantly lower than those of high protein diet group (P<0.05). The Longissimus dorsi cystine content of 0.1% GAA group was significantly lower than that of 0 and 0.2% GAA groups (P<0.05). 4) The Longissimus dorsi glutathione peroxidase (GSH-Px) activity of 0.2% GAA group was significantly lower than that of 0 and 0.1% GAA groups (P<0.05). It is concluded that when 0.2% GAA of the concentrate is added to the low protein diet, the dynamic balance of plasma hormone indices, serum biochemical indices, meat quality, muscle amino acids contents and muscle antioxidant indices is optimised, which is suitable for yak breeding.

This experiment aimed to investigate the effects of rice straw-cassava residue fermentation wrapping (RS-CRFW) replacing silage corn on growth performance, nutrient apparent digestibility and fecal microbiota of water buffaloes. Thirty 15 to 18-month-old growing female water buffaloes with an average body weight of (319.32±24.28) kg were randomly divided into 3 groups with 10 replicates per group and 1 water buffaloe per replicate. Group A was fed a total mixed ration consisting of conventional roughages (silage corn, peanut vines and distiller’s grains), while group B and group C were used RS-CRFW replacing 12.46% and 24.91% silage corn in the conventional roughages, respectively. The pre-trial period was 14 days, and the trial period was 60 days. The results showed as follows: 1) compared with the group A, the average daily gain (ADG) of group B was no significant difference (P>0.05), the ADG of group C was significantly decreased (P<0.05), and the dry matter intake of group B and group C was significantly decreased (P<0.05). 2) Compared with the group A, the apparent digestibility of neutral detergent fiber (NDF), acid detergent fiber (ADF) and organic matter (OM) of group B were no significant difference (P>0.05), and the apparent digestibility of NDF, ADF and OM of group C were significantly decreased (P<0.05). 3) Compared with the group A, the fecal microbiota Chao1 index and Observed species index of group B were no significant difference (P>0.05), and the fecal microbiota Chao1 index and Observed species index of group C were significantly decreased (P<0.05). Compared with the group A, the relative abundance of Bacteroides in feces of group B was increased by 36.59% (P>0.05). In summary, the RS-CRFW replacing 12.46% silage corn in the diet can improve the gut microbiota structure, and has no negative effects on the ADG and apparent digestibility of NDF, ADF and OM of water buffaloes.

This study aimed to investigate the growth characteristics, feed efficiency, and residual feed intake (RFI) variations of multiparous fine wool sheep at 80 to 160 days of age, as well as the correlations among these parameters and to further compare the differences among multiparous fine wool sheep with different RFI. The experimental population consisted of 139 healthy multiparous fine wool sheep male lambs housed in standardized single pens. Sheep were only weaned at 56 days of age, and the experiment was divided into transition (14 d), pre-test (10 d), and test (80 d) periods. During the test period, feed intake was recorded daily to calculate average daily feed intake (ADFI), and body weight (BW) and body measurement data were recorded every 20 days to calculate average daily gain (ADG) and feed conversion rate (FCR). According to the mean (80 to 160 days of age) and standard deviation (SD) of individual RFI, the experimental flocks were divided into three groups: high RIF group (RFI>mean+0.5SD, n=40), moderate RFI group (mean-0.5SD≤RFI≤mean+0.5SD, n=59) and low RFI group (RFI<mean-0.5SD, n=40). The results showed as follows: 1) during the age of 80 to 160 days, multiparous fine wool sheep exhibited an ADG of 0.30 kg, a FCR of 5.11, an ADFI of 1.53 kg, and a metabolic body weight (MBW) of 13.18 kg. With increasing age, BW and body measurements increased gradually, while their coefficients of variation decreased progressively. 2) Traits such as BW, body length (BL), body height (BH), and chest circumference (ChC) all showed significant or extremely significant positive correlations with RFI within the corresponding age stages (P<0.05 or P<0.01). RFI was significant or extremely significant negative correlations with ADG and ADFI (P<0.05 or P<0.01), but showed no significant correlation with FCR (P>0.05). Additionally, cannon circumference (CaC) and scrotal circumference (SC) displayed high correlations with chest circumference (ChC) and body height (BH) at various age stages. 3) Group comparisons indicated that the low-RFI group had significantly lower RFI, ADFI, and FCR compared with the medium-RFI group (P<0.05), and the medium-RFI group had significantly lower values than the high-RFI group (P<0.05). Significant differences were observed among the groups for certain growth traits (e.g., BH, BL, ChC, and CaC; P<0.05), whereas no significant differences were detected in rump height, chest width, hip width, and scrotal circumference (P>0.05). In conclusion, compared with the traditional FCR, RFI as an evaluation index can not only more accurately reflect feed efficiency, but also help to rationally regulate animal feed intake. However, the feeding behavior of animals is affected by multiple factors such as environmental factors, individual physiological characteristics, and diet quality, so it is necessary to comprehensively consider the mechanism of these factors on feed intake in practical applications.

This experiment was conducted to investigate the effects of selenium nanoparticles (SeNPs) on growth performance, serum indexes, rumen fermentation parameters and microflora structure of Shaanbei white cashmere goats. A single-factor randomized grouping design was adopted, and fifty-six 5-month-old Shaanbei white cashmere male lambs with similar body weight [(22.0±1.5) kg] were selected and randomly divided into 4 groups with 14 lambs in each group. Lambs in the 4 groups were fed diets supplemented with 0, 0.09, 0.18 and 0.27 mg/kg SeNPs (calculated as selenium) in the basal diet, and the actual selenium contents in the diets were 0.074 (group Ⅰ), 0.164 (group Ⅱ), 0.254 (group Ⅲ) and 0.344 mg/kg (group Ⅳ), respectively. The feeding experiment lasted for 75 days, with a 15-day pre-test period and a 60-day formal test period. The results showed as follows: 1) compared with group Ⅰ, the average daily gain (ADG) in group Ⅲ was significantly increased (P<0.05), and the average daily feed intake (ADFI) in groups Ⅱ, Ⅲ and Ⅳ was significantly increased (P<0.05). The feed-to-gain ratio (F/G) in group Ⅲ was significantly lower than that in the other 3 groups (P<0.05). 2) Compared with group Ⅰ, the serum glucose (GLU) content in groups Ⅲ and Ⅳ was extremely significantly increased (P<0.01), and the serum urea nitrogen (UN) content was extremely significantly decreased (P<0.01); the serum superoxide dismutase (SOD) activity in groups Ⅱ, Ⅲ and Ⅳ was extremely significantly increased (P<0.01), and the serum glutathione peroxidase (GSH-Px) and catalase (CAT) activities were significantly increased (P<0.05); the serum malondialdehyde (MDA) content in group Ⅲ was significantly decreased (P<0.05). 3) Compared with group Ⅰ, the concentrations of ammonia nitrogen (NH₃-N) and microbial protein (MCP) in rumen fluid in group Ⅲ were significantly increased (P<0.05). The concentrations of acetic acid, propionic acid, butyric acid and total volatile fatty acids in rumen fluid in group Ⅲ were the highest among the 4 groups. Among them, the concentrations of acetic acid and total volatile fatty acids in rumen fluid in group Ⅲ were significantly higher than those in groups Ⅰ and Ⅳ (P<0.05), the propionic acid concentration was significantly higher than that in group Ⅳ (P<0.05), and the butyric acid concentration was significantly higher than that in the other 3 groups (P<0.05). 4) Compared with group Ⅰ, the rumen microbial Chao1 index in group Ⅲ was significantly increased (P<0.05). At the phylum level, the relative abundance of Bacteroidota in rumen in group Ⅳ was significantly lower than that in the other 3 groups (P<0.05), and the relative abundance of Firmicutes was significantly higher than that in group Ⅱ (P<0.05); at the genus level, the relative abundance of Prevotella in rumen in group Ⅲ was extremely significantly higher than that in groups Ⅰ and Ⅳ (P<0.01), and the relative abundance of Quinella in rumen in groups Ⅱ and Ⅳ was extremely significantly lower than that in group Ⅰ (P<0.01). In conclusion, dietary supplementation with appropriate amount of SeNPs can increase the ADG and ADFI, decrease the F/G, and improve the serum biochemical indexes and antioxidant capacity of Shaanbei white cashmere goats; it can also regulate rumen microflora structure and promote rumen fermentation. Based on comprehensive analysis, the optimal selenium supplementation level using SeNPs as the selenium source is 0.18 mg/kg.

This experiment was conducted to investigate the effects of dietary palm kernel meal (PKM) on the flavor of different muscle parts of Tibetan sheep. Sixty Tibetan sheep aged of 2 to 3 months with a similar body weight of (18±3) kg were selected and randomly divided into 2 groups, with 6 replicates in each group and 5 sheep in each replicate. Sheep in the control group were fed a basal diet, while those in the PKM group were fed an experimental diet in which 18% PKM was supplemented into the concentrate supplement. The experiment lasted for 90 days after a pre-test of 14 days. After the experiment, the samples of longissimus dorsi, biceps femoris and triceps brachii were collected, and the composition and contents of volatile substances were determined by gas chromatography-ion mobility spectrometry (GC-IMS) technology. The results showed as follows: 1) a total of 36 volatile substances were detected from different muscle parts of Tibetan sheep, including 12 aldehydes, 11 alcohols, 9 ketones, 3 esters and 1 heterocyclic substance. Compared with the control group, the contents of volatile substances in different muscle parts in the PKM group were increased. 2) Taking the relative odor activity value (ROVA)>1 and variable importance projection (VIP)>1 as the screening criteria, the key flavor substances of different muscle parts in the control group were hexanal monomer and acetoin, while in the PKM group, hexanal dimer and 1-nonanal monomer were added. 3) The results of fingerprint and principal component analysis (PCA) indicated that there were obvious differences in volatile substances among different muscle parts in the PKM group, and the contents of aldehydes and alcohols in triceps brachii were higher than that in longissimus dorsi and biceps femoris. In conclusion, dietary PKM can effectively improve the flavor of different muscle parts of Tibetan sheep, especially in triceps brachii.

This study aimed to investigate the effects of barley hay on growth performance, slaughter performance and meat quality of mutton sheep. Forty-five weaned Dorper×thin-tailed Han crossbred lambs with similar body weight [(33.93±1.11) kg] were randomly assigned to five groups, with three replicates per group and three lambs per replicate. The control group was fed a basal diet, and the experimental groups were used 25% (BH25 group), 50% (BH50 group), 75% (BH75 group), and 100% (BH100 group) barley hay replacing the roughage (corn straw and wildrye) in the basal diet, respectively. The pre-experimental period lasted for 15 days, and the experimental period lasted for 60 days. The results showed as follows: 1) the feed to gain ratio of BH50, BH75 and BH100 groups was significantly lower than that of the control group (P<0.05). 2) The loin eye area of the BH75 group was significantly higher than that of the control group (P<0.05). 3) The muscle cooked meat percentage of the BH50 group was significantly higher than that of the control group (P<0.05), and the muscle redness (a^*) value of the BH100 group was significantly higher than that of the control group (P<0.05). Compared with the control group, the muscle yellowness (b^*) value of experimental groups showed a decreasing trend (P=0.091), and the muscle ether extract content showed an increasing trend (P=0.069). 4) The muscle glutamic acid (Glu) content of the BH100 group was significantly higher than that of the control group (P<0.05). 5) The muscle lauric acid (C12∶0) content of the BH75 group was significantly higher than that of the control group (P<0.05), and the muscle pentadecenoic acid (C15∶1) and arachidonic acid (C20∶4) contents of the BH25 group were significantly higher than those of the control group (P<0.05). Compared with the control group, the muscle total polyunsaturated fatty acids (∑PUFAs) content of experimenal groups showed an increasing trend (P=0.094). In conclusion, the barley hay replacing 50% or more of corn straw and wildrye in the basal diet not only improves feed utilization efficiency in mutton sheep, but also demonstrates positive effects on improving the slaughter performance, enhancing the meat quality and optimizing the amino acid and fatty acid composition of muscle.

This experiment was conducted to investigate the effects of dietary arginine (Arg) supplementation on growth performance, blood indexes and hepatic glucose metabolism of juvenile Songpu mirror carp. A total of 360 healthy juvenile Songpu mirror carp with an initial body weight of (6.84±0.02) g were randomly divided into 5 groups with 4 replicates per group and 18 fish per replicate. The fish in 5 groups were fed isonitrogenous and isoenergetic diets supplemented with 0 (C0 group), 0.6% (C0.6 group), 1.2% (C1.2 group), 1.8% (C1.8 group) and 2.4% (C2.4 group) Arg, respectively. The trial lasted for 8 weeks. The results showed as follows: 1) compared with the C0 group, the weight gain rate (WGR) in all Arg-supplemented groups was significantly increased (P<0.05), and the feed conversion ratio (FCR) was significantly decreased(P<0.05); the condition factor (CF) in the C1.2, C1.8 and C2.4 groups was significantly increased (P<0.05); the protein efficiency ratio (PER) in the C1.8 and C2.4 groups was significantly increased (P<0.05). Broken line regression analysis based on WGR indicated that the optimal dietary Arg requirement for juvenile Songpu mirror carp was 1.85% of dry matter or 5.53% of dietary protein. 2) Compared with the C0 group, the content of triglyceride (TG) in serum in the C1.2, C1.8 and C2.4 groups was significantly decreased (P<0.05); the contents of total cholesterol (T-CHO) and high-density lipoprotein cholesterol (HDL-C) in serum in the C2.4 group were significantly decreased (P<0.05). 3) The activities of hepatic glucokinase (GK) and glycogen synthase kinase 3β (GSK3β) in the C2.4 group were significantly higher than those in other groups (P<0.05), while the activity of hepatic phosphofructokinase (PFK) was significantly lower than that in other groups (P<0.05). Compared with the C0 group, the activity of hepatic hexokinase (HK) in the C1.2 and C1.8 groups was significantly increased (P<0.05); the activity of hepatic 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 2 (PFKFB2) in the C1.8 and C2.4 groups was significantly increased (P<0.05); the contents of hepatic insulin receptor (IR), phosphatidylinositol 3-kinase (PI3K), protein kinase B (AKT), glucose transporter 2 (GLUT2) and glucose transporter 4 (GLUT4) in the C1.2, C1.8 and C2.4 groups were significantly increased (P<0.05); and the content of hepatic phosphorylated protein kinase B (p-AKT) in the C1.2 group was significantly increased (P<0.05). 4) Among hepatic genes related to glucose transport, compared with the C0 group, the mRNA relative expression levels of AKT in the C0.6 and C1.2 groups, protein kinase B substrate 160 (AS160) in all Arg-supplemented groups, and GLUT2 in the C0.6, C1.2 and C1.8 groups were significantly increased (P<0.05). Among hepatic genes related to glycolysis, compared with the C0 group, the mRNA relative expression levels of PFKFB2 in the C1.2 group, GK in the C1.2 and C1.8 groups, and HK in the C0.6, C1.2 and C1.8 groups were significantly increased (P<0.05). Among hepatic genes related to gluconeogenesis, the mRNA relative expression level of forkhead box protein O1 (FOXO1) in the C1.2, C1.8 and C2.4 groups was significantly higher than that in the C0 and C0.6 groups (P<0.05); compared with the C0 group, the mRNA relative expression levels of glucose-6-phosphatase (G6Pase) in the C2.4 group and phosphoenolpyruvate carboxykinase (PEPCK) in all Arg-supplemented groups were significantly decreased (P<0.05). Among hepatic genes related to glycogen synthesis, the mRNA relative expression level of glycogen synthase (GSase) in the C0.6 and C1.2 groups was significantly higher than that in other groups (P<0.05). In conclusion, dietary supplementation with 0.6% to 2.4% Arg can improve the growth performance and promote hepatic glucose metabolism of juvenile Songpu mirror carp.

This experiment aimed to explore the effects of fishmeal replacement with black soldier fly larvae meal on growth performance, serum biochemical indices and gut microflora of largemouth bass (Micropterus salmoides). A total of 300 juvenile largemouth bass with average body weight of (72.67±0.27) g were randomly divided into 4 groups with 3 replicates per group and 25 fish per replicate. Fish in 4 groups were fed experimental diets which 0 (FM group), 15% (BSFL15 group), 30% (BSFL30 group) and 45% (BSFL45 group) fish meal were replaced by black soldier fly larvae meal in the basal diet, respectively. The experiment lasted for 56 weeks. The results showed as follows: 1) the feed conversion ratio of BSFL30 group was significantly higher than that of FM group (P<0.05). The condition factor of BSFL30 group and BSFL45 group was significantly lower than that of FM group (P<0.05). 3) The serum total antioxidant capacity (T-AOC) of BSFL30 group and BSFL45 group was significantly higher than that of FM group (P<0.05). The serum catalase (CAT) activity of BSFL15 group and BSFL30 group was significantly higher than that of FM group (P<0.05). The serum acid phosphatase (ACP) activity of BSFL45 group was significantly higher than that of FM group (P<0.05). The serum glucose (GLU) content of BSFL45 group was significantly lower than that of FM group (P<0.05). The contents of total cholesterol (TC), triglycerides (TG) and low-density lipoprotein cholesterol (LDL-C) in serum of BSFL30 group were significantly lower than those of FM group (P<0.05). 3) Compared with FM group, at the phylum level, the gut Firmicutes relative abundance of BSFL15 group, BSFL30 group and BSFL45 group was increased, while the Fusobacteriota relative abundance was decreased; at the genus level, the gut Mycoplasma relative abundance of BSFL15 group, BSFL30 group and BSFL45 group was increased, while the Cetobacterium relative abundance was decreased. In conclusion, replacing 15% to 45% of fish meal with black soldier fly larvae meal in diet has a potential negative impact on the growth performance of largemouth bass, and affects the serum biochemical indices and gut microbiota structure. Under these experimental conditions, it is recommended that the proportion of black soldier fly larvae meal replacing fish meal in diet for largemouth bass should not exceed 15%.

To investigate the effects of chlorogenic acid (CGA) levels in diets on growth performance, lipid metabolism, immune function and antioxidant capacity of Leuciscus waleckii, the single-factor factorial design was adopted in this study. A total of 600 fish with an initial body mass of (3.24±0.05) g/fish were randomly divided into 5 groups with 3 replicates per group and 40 fish in each replicate. The 5 groups were fed different levels of CGA [0 (CK group), 0.02% (C1 group), 0.04% (C2 group), 0.06% (C3 group) and 0.08% (C4 group)], respectively, and the feeding experiment lasted for 8 weeks. The results showed as follows: compared with CK group, adding 0.04% to 0.06% CGA significantly improved the growth performance and feed utilization of amur ide (P<0.05); adding 0.04% CGA significantly increased serum high-density lipoprotein cholesterol (HDL-C) content (P<0.05), and significantly decreased serum low-density lipoprotein cholesterol (LDL-C), triglyceride (TG) and total cholesterol (TC) contents (P<0.05); it significantly increased the activity of adipose triglyceride lipase (ATGL) in hepatopancreas (P<0.05), and decreased the activities of acetyl coenzyme A carboxylase (ACC) and ATGL and the content of TG in hepatopancreas (P<0.05); it also significantly increased the relative expression of peroxisome proliferator-activated receptor-β (PPAR-β) mRNA in hepatopancreas (P<0.05), and significantly decreased the relative expression levels of fatty acid synthase (FAS), ACC-1 and peroxisome proliferator-activated receptor-γ (PPAR-γ) mRNA in hepatopancreas (P<0.05). It promoted lipolysis in serum and hepatopancreas; the contents of immunoglobulin M (IgM), complement 3 (C3) and complement 4 (C4) in serum and the activities of lysozyme (LZM) and alkaline phosphatase (AKP) in serum were significantly increased by 0.04% CGA supplementation (P<0.05), and the relative expression level of growth transforming factor-β (TGF-β) mRNA in hepatopancreas was significantly increased (P<0.05); the relative expression level of nuclear factor-κBp65 (NF-κBp65), myeloid differentiation factor 88 (MyD88) and tumor necrosis factor-α (TNF-α) mRNA in hepatopancreas was significantly reduced (P<0.05), and the immune function was enhanced; adding 0.04% CGA significantly increased serum total antioxidant capacity (T-AOC) and activities of catalase (CAT), total superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-Px) (P<0.05), and significantly decreased serum malondialdehyde (MDA) content (P<0.05); It significantly increased the activities of T-AOC, T-SOD, CAT and GSH-Px in hepatopancreas (P<0.05), and decreased the content of MDA in hepatopancreas (P<0.05); addition of 0.04% CGA significantly increased the relative expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1) and CAT mRNA in hepatopancreas (P<0.05); it also significantly reduced the relative expression levels of Keap-1 mRNA (P<0.05). In conclusion, dietary supplementation of 0.04%CGA can significantly improve growth performance and feed utilization of amur ide, promote hepatopancreas lipdecomposition, inhibit lipid deposition, enhance immune function by activating nuclear transcription factor signaling pathway and enhance antioxidant capacity by activating Keap1-Nrf2 signaling pathway.

In this experiment, to explore the effects of diet with high level of faba bean on the muscle volatile flavor substances composition of genetic improvement of farmed tilapia (GIFT, Oreochromis niloticus), fifty GIFT with initial body weight of (402.32±8.59) g were randomly divided into 2 groups, with 5 replicates per group and 5 fish per replicate. During the feeding period of 49 days, the two groups of experimental fish were fed with isonitrogenous and isolipidic diets containing 0 (control group, denoted as G0 group) and 70% (experimental group, denoted as G70 group) faba bean, respectively. The two groups of tilapia muscle samples were sent for the determination of flavoromics using comprehensivetwo-dimensional gas chromatography-time-of-flight mass spectrometry (GC×GC-TOF MS). The results showed as follows: 1) a total of 920 volatile flavor substances were detected in tilapia muscle samples in two groups, 707 in G0 group, 633 in G70 group, and a total of 420 volatile flavor substances were detected in both groups. 2) The volatile flavor substances in the tilapia muscle mainly included 7 categories, including alcohols, aldehydes, carboxylic acids, esters, heterocyclic compounds, hydrocarbons and ketones, among which G0 group had the highest relative content of alcohols (32.97%), followed by ketones (10.82%), while G70 group had the highest relative content of alcohols (40.52%), followed by esters (13.98%). 3) It was found that there were 10 kinds of volatile flavor substances in tilapia muscle with significant differences between the two groups. Compared with group G0, the contents of 6-methyl-5-heptene-2-ketone (C₁₁H₂₀O), 5-methyl-2-hexanone (C₇H₁₄O), (Z)-undecen-2-one (C₁₁H₂₀O), ethyl phenylacetate (C₁₀H₁₂O₂), 1-octen-3-ol (C₈H₁₆O), 1-methylpyrrole (C₅H₇N), 2-hydroxy-3-pentanone (C₅H₁₀O₂) in the group G70 were significantly decreased (P<0.05), while the contents of 6-methyl-2,4-heptanedione (C₈H₁₄O₂), ethyl isovalerate (C₇H₁₄O₂) and 1-mercapto-2-propanone (C₃H₆OS) were significantly increased (P<0.05). The key volatile flavor substances of tilapia muscle are 2,3-butanedione (C₄H₆O₂), 2-methylbutyraldehyde (C₅H₁₀O),2-heneicosane (C₁₁H₂₄) and 2-pentylfuran (C₉H₁₄O). Compared with G0 group, the relative odor activity value (ROVA) of C₄H₆O₂ (contributing to butter flavor) in G70 group was decreased, while the ROVA of C₅H₁₀O (contributing to cocoa flavor) was increased. To sum up, under the experimental conditions, adding high level (70%) faba bean to the diet can improve the relative contents of alcohols and esters in the muscle of GIFT, increase the ROVA of C₅H₁₀O and decrease the ROVA of C₄H₆O₂, which can change the fat flavor of tilapia muscle. Besides, diets supplemented with high level of faba bean slightly reduces the fruit flavor of muscle of GIFT, and inhibits the action of fishy substances, reducing the earthy smell of muscle.

This experiment aimed to investigate the effects of diets supplemented with eucalyptus branch biochar on growth performance, antioxidant capacity and aquatic water quality of largemouth bass (Micropterus salmoides). Five isonitrogenous and isolipidic experimental diets were formulated by adding 0, 2.5, 5.0, 10.0 and 20.0 g/kg of eucalyptus branch biochar to the basal diet, designated as groups C0, C2.5, C5, C10 and C20, respectively. Six hundred largemouth bass with an initial body weight of (13.34±0.02) g were randomly allocated into five groups (4 replicates per group with 30 fish per replicate) and fed the corresponding experimental diets for a 56-day feeding trial. The results showed as follows: 1) the final average body weight and specific growth rate of largemouth bass in the eucalyptus branch biochar addition groups (groups C2.5, C5, C10 and C20) were significantly higher than those in the control group (group C0) (P<0.05), with the highest in the C2.5 group. The weight gain rate of largemouth bass in the C2.5 group was significantly higher than that in other groups (P<0.05), and its feed conversion ratio (FCR) was significantly lower than that in other groups (P<0.05). There were no significant differences in survival rate, condition factor, viscera somatic index, hepatosomatic index and intestine somatic index of largemouth bass among all groups (P>0.05). 2) Compared with the C0 group, the serum total antioxidant capacity (T-AOC) of largemouth bass in the group C10 was significantly increased (P<0.05); the activity of serum catalase (CAT) in the groups C2.5 and C5 was significantly increased (P<0.05); the contents of serum malondialdehyde (MDA) in the groups C10 and C20 was significantly decreased (P<0.05). The activity of liver CAT in the groups C2.5, C10 and C20 was significantly higher than that in the group C0 (P<0.05); the content of liver MDA in the eucalyptus branch biochar addition groups was significantly lower than that in the C0 group (P<0.05). Compared with the group C0, the T-AOC in the intestine in the eucalyptus branch biochar addition groups was significantly increased (P<0.05), and the content of MDA was significantly decreased (P<0.05). 3) With the extension of the culture time, the contents of total phosphorus (TP), total nitrogen (TN), ammonia nitrogen (NH₃-N) and nitrite nitrogen ($\mathrm{NO}_{2}^{-}$-N) in the aquatic water of each group showed a gradual upward trend. Among them, the increasing rates of TP content in group C5 and TN content in group C2.5 were slower than those in other groups. From the 35th to the 56th day, the aquatic water TP content in the eucalyptus branch biochar addition groups was significantly lower than that in the group C0 (P<0.05). From the 42nd to the 56th day, the aquatic water TN content in the eucalyptus biochar addition groups was significantly lower than that in the group C0 (P<0.05). From the 14th to the 56th day, the aquatic water $\mathrm{NO}_{2}^{-}$-N content in the eucalyptus branch biochar addition groups was significantly lower than that in the group C0 (P<0.05). In summary, under the conditions of this experiment, the addition of 2.5 to 5.0 g/kg eucalyptus branch biochar in the diet can improve the growth performance and enhance the antioxidant capacity of largemouth bass, and improve the aquatic water quality by reducing.the contents of TP, TN and $\mathrm{NO}_{2}^{-}$-N in the aquatic water.

The purpose of this study was to investigate the protective roles of Astragalus membranaceus (AM) extracts on pellet feed and its effects on digestion, hypoxia tolerance, and immunity in Cyprinus carpio var. Jian. Five experimental diets were formulated by adding 0 (blank) and 0.5% AM petroleum ether extract (PEE), 0.5% AM ethyl acetate extract (EAE), 0.5% AM ethanol extract (EE) and 0.5% AM aqueous extract (AQE) to the basal diet, respectively. A total of 450 carp with a body weight of (9.41±0.18) g were randomly divided into 5 groups with 3 replicates per group and 30 carp per replicate. The carps in the 5 groups were fed the basal diet and diets containing different Astragalus extract for 15 days. The results showed that compared with the blank group, dietary supplementation with Astragalus PEE, EAE, and EE significantly reduced the contents of peroxides, conjugated dienes, and malondialdehyde (MDA) in pellet feed (P<0.05); all four Astragalus extracts added to the feed significantly decreased the mold growth area in pellet feed (P<0.05). Compared with the blank group, dietary supplementation with Astragalus PEE, EAE, and AQE significantly increased the feeding rate and challenge survival rate of carp (P<0.05); dietary supplementation with Astragalus PEE and EAE significantly prolonged the anoxia duration of carp (P<0.05); while dietary supplementation with Astragalus EAE significantly reduced the oxygen consumption rate (P<0.05). Compared with the blank group, dietary supplementation with all four Astragalus extracts significantly increased the plasma lysozyme content (P<0.05) and significantly decreased the glucose content in carp (P<0.05); dietary supplementation with Astragalus PEE, EAE, and AQE significantly increased the plasma total amino acid content (P<0.05); dietary supplementation with Astragalus EAE, EE, and AQE significantly increased the plasma total protein content (P<0.05); whereas dietary supplementation with Astragalus EAE and AQE significantly reduced the plasma ammonia content (P<0.05). Compared with the blank group, dietary supplementation with all four Astragalus extracts significantly increased the intestinal reduced glutathione (GSH) content, as well as the activities of anti-superoxide anion (ASA), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) (P<0.05), while significantly decreasing the contents of hydrogen peroxide and MDA in carp (P<0.05); dietary supplementation with Astragalus EAE and EE significantly increased the intestinal chymotrypsin (CTS) activity (P<0.05); dietary supplementation with Astragalus EAE significantly increased the intestinal lipase (LPS) activity and anti-hydroxyl radical activity (P<0.05). Compared with the blank group, dietary supplementation with all four Astragalus extracts significantly increased the hepatopancreatic GSH content, as well as the activities of trypsin, LPS, α-amylase, glutamic-pyruvic transaminase (GPT), and lactate dehydrogenase (LDH) in carp (P<0.05); dietary supplementation with Astragalus EAE, EE, and AQE significantly increased the hepatopancreatic CTS and GPx activities (P<0.05); dietary supplementation with Astragalus EAE and EE significantly increased the hepatopancreatic ASA activity (P<0.05). Compared with the blank group, dietary supplementation with all four Astragalus extracts significantly increased the gill LDH, SOD, and GPx activities (P<0.05), while decreasing the MDA content in carp (P<0.05); dietary supplementation with Astragalus EAE and AQE increased the gill glutamic-oxaloacetic transaminase (GOT) and ASA activities (P<0.05). Compared with the blank group, dietary supplementation with all four Astragalus extracts significantly increased the spleen GSH content (P<0.05), as well as the SOD and GPx activities (P<0.05), while decreasing the MDA content in carp (P<0.05); dietary supplementation with Astragalus EAE, EE, and AQE increased the splenic CAT activity (P<0.05). These results indicate that AM extracts reduce lipid oxidation, especially EE, and inhibit mold growth, especially AQE, in pellet feeds. Dietary AM extracts improve the digestive and immune functions as well as hypoxia tolerance and antioxidant capacity in carp, especially EAE.

This experiment was conducted to investigate the effects of different supplemental levels of dandelion extract (DE) in low fish meal diets on growth performance, muscle quality and serum biochemical indices of juvenile Litopenaeus vannamei. Six hundred healthy juvenile Litopenaeus vannamei with an initial body weight of (0.22±0.00) g were selected and randomly divided into 5 groups, with 3 replicates in each group and 40 shrimp in each replicate. Each group was fed isonitrogen and isolipid diets supplemented with 0 (control group, DE0 group), 0.30% (DE3 group), 0.60% (DE6 group), 0.90% (DE9 group), and 1.50% (DE15 group) DE in the basal diet, respectively. The experiment lasted for 8 weeks. The results showed as follows: 1) compared with DE0 group, the final body weight, weight gain rate, specific growth rate and feeding rate in DE3 and DE6 groups were significantly increased (P<0.05), and the feed conversion ratio was significantly decreased (P<0.05). 2) Compared with DE0 group, the crude protein content in whole shrimp in DE15 group was significantly increased (P<0.05); except for DE6 group, the crude lipid content in whole shrimp in the other DE supplemental groups was significantly decreased (P<0.05); the crude protein content in muscle in each DE supplemental group was significantly increased (P<0.05), while the crude lipid content in muscle was significantly decreased (P<0.05). 3) Compared with DE0 group, the contents of total amino acids, total essential amino acids, total delicious amino acids and total aromatic amino acids in muscle in DE3 group were significantly increased (P<0.05), and the contents of total polyunsaturated fatty acids (PUFA) and total n-3 PUFA in muscle in DE3 group were significantly increased (P<0.05). 4) Compared with DE0 group, the muscle hardness, gumminess and chewiness in each DE supplemental group were significantly increased (P<0.05), and the muscle cooking water loss rate was significantly decreased (P<0.05); the muscle springiness and cohesiveness in DE3, DE9 and DE15 groups were significantly improved (P<0.05); the muscle shear force in DE6, DE9 and DE15 groups was significantly increased (P<0.05), and the muscle steaming water loss rate was significantly decreased (P<0.05). 5) Compared with DE0 group, the serum total protein content in DE3, DE6 and DE9 groups was significantly increased (P<0.05), and the serum low-density lipoprotein cholesterol content was significantly decreased (P<0.05); the serum high-density lipoprotein cholesterol content and the acid phosphatase activity in each DE supplemental group were significantly increased (P<0.05); the serum alkaline phosphatase activity in DE3, DE6 and DE15 groups was significantly increased (P<0.05); the activities of serum alanine aminotransferase and aspartate aminotransferase in DE3 and DE6 groups were significantly decreased (P<0.05). In conclusion, an appropriate supplementation level of DE in low fish meal diets can promote the growth of juvenile Litopenaeus vannamei, improve muscle quality and serum biochemical indices. Taking the weight gain rate as the evaluation index, the appropriate supplementation level of DE in low fish meal diets for juvenile Litopenaeus vannamei is 0.40% according to the broken line model.

This experiment was conducted to explore the effects of different stocking densities on growth performance, digestive capacity and muscle nutrients of Penaeus monodon under low-salinity condition, and determine the appropriate stocking density. A total of 250 healthy Penaeus monodon with an average body weight of (3.02±0.30) g and an average body length of (5.88±0.52) cm were selected. The water salinity was set at (4.5±0.5) ‰, and five stocking densities were set, that was, each 6, 9, 12, 15 and 18 shrimps were raised in an experimental tank (with a water volume of 0.12 m³, 80 cm×50 cm×30 cm), corresponding to the stocking densities of 45, 70, 95, 120 and 145 shrimps/m³, which were labeled as M45, M70, M95, M120 and M145 groups, respectively. Three parallel tanks were set up for each stocking density. The experiment lasted for 42 days. The results showed as follows: 1) the final body weight, weight gain rate and specific growth rate in M45, M70 and M95 groups were significantly higher than those in M120 and M145 groups (P<0.05), and the feeding rate was significantly lower than that in M145 group (P<0.05); the survival rate in M45 and M70 groups was significantly higher than that in the other groups (P<0.05), the condition factor was significantly higher than that in M95 and M120 groups (P<0.05), the protein efficiency ratio was significantly higher than that in M120 and M145 groups (P<0.05), and the feed coefficient was significantly lower than that in M120 and M145 groups (P<0.05). 2) The amylase activity in hepatopancreas in M45 and M70 groups was significantly higher than that in the other groups (P<0.05); the activities of trypsin and lipase in hepatopancreas in M70 group were significantly higher than those in the other groups (P<0.05), and the mRNA relative expression levels of α-amylase, trypsin 1 and lipase maturation factor 2 (LMF2) in hepatopancreas were significantly higher than those in the other groups (P<0.05). 3) The crude protein content in muscle in M70 and M120 groups was significantly higher than that in the other groups (P<0.05), the crude ash content in muscle in M70 group was significantly lower than that in the other groups (P<0.05), and the moisture content in muscle in M145 group was significantly higher than that in the other groups (P<0.05). 4) Except for cystine and alanine, the contents of various amino acids, delicious amino acids, sweet amino acids, essential amino acids, non-essential amino acids and total amino acids in muscle in M145 group were significantly lower than those in the other groups (P<0.05). The essential amino acid index (EAAI) in muscle in each group ranged from 61.33% to 75.61%, among which M70 group had the highest index. Taking amino acid score (AAS) and chemical score (CS) as evaluation indices, valine was the main limiting amino acid in muscle. 5) The total saturated fatty acid content in muscle in M70 and M95 groups was significantly higher than that in the other groups (P<0.05), the total monounsaturated fatty acid content in muscle in M145 group was significantly higher than that in the other groups (P<0.05), the total polyunsaturated fatty acid content in muscle in M45 and M70 groups was significantly higher than that in M95 group (P<0.05), and the eicosapentaenoic acid (EPA)+docosahexaenoic acid (DHA) content in muscle in M70 group was significantly higher than that in M95 and M145 groups (P<0.05). The polyene index (PI) in muscle in M45 group was significantly higher than that in the other groups except M120 group (P<0.05). The index of atherogenicity (IA, 0.37 to 0.44) and index of thrombogenicity (IT, 0.38 to 0.46) in muscle in each group were all lower than the safe value (1.00). In conclusion, the stocking density of ≤70 shrimps/m³ under low-salinity condition is favorable to promote the growth of Penaeus monodon, improve the digestive capacity, and have a high food value.

This experiment was conducted to compare the differences of nutrient apparent digestibility, growth performance and nitrogen metabolism indexes of Beagle dogs, Arctic foxes and Ussuri raccoon dogs, and to establish their prediction equations. Ten adult female Beagle dogs with body weight of (18.53±3.25) kg, ten Arctic foxes with body weight of (6.76±0.63) kg, and ten Ussuri raccoon dogs with body weight of (6.43±1.37) kg were selected, each animal independently as one group, divided into 3 groups with 10 animals in each group. The experiment consisted of 5 stages, each stage included 10 days, each group was fed the same diet at the same stage, and a total of 5 kinds of diets were used. The results showed as follows: 1) the apparent digestibility of crude protein (CP), ether extract (EE) and carbohydrates (CHO) of Beagle dogs was significantly higher than that of Arctic foxes (P<0.05), and had no significant difference compared with Ussuri raccoon dogs (P>0.05). 2) The average daily gain (ADG) and average daily feed intake (ADFI) of Beagle dogs were significantly lower than those of Arctic foxes (P<0.05), and had no significant difference compared with Ussuri raccoon dogs (P>0.05). 3) The nitrogen intake (NI), fecal nitrogen (FN), and retention nitrogen (RN) of Beagle dogs were significantly lower than those of Arctic foxes (P<0.05), and had no significant difference compared with Ussuri raccoon dogs (P>0.05). 4) The apparent digestibility of dry matter (DM), calcium (Ca), phosphorus (P) and NI showed significant positive correlations between Beagle dogs and Arctic foxes (P<0.05). The apparent digestibility of DM, CP, EE, crude ash (Ash), Ca, P and ADFI, feed to gain ratio (F/G) showed significant positive correlations between Beagle dogs and Ussuri raccoon dogs (P<0.05 or P<0.01). 5) Twelve prediction equations were established in this experiment, with four prediction equations of Arctic foxes to Beagle dogs, and 8 prediction equations of Ussuri raccoon dogs to Beagle dogs. In conclusion, compared with Arctic foxes, the Ussuri raccoon dogs are more similar to Beagle dogs in the nutrient apparent digestibility, growth performance and nitrogen metabolism indexes, the data correlation is significant, and more prediction equations have been established. Ussuri raccoon dogs may be superior to Arctic foxes as model animals for Beagle dogs.

This experiment aimed to investigate the effects of fermented mulberry leaves (FML) on plasma and liver metabolites of finishing pigs. A total of 18 Duroc×Landrace×Large White barrow pigs (78.19±2.05) kg were randomly assigned to 2 groups with 9 replicates per group and 1 pig per replicate. Pigs in control group were fed a basal diet, and pigs in FML group were fed the basal diet supplemented with 10% FML. The test period was 69 days. The results showed as follows: 1) compared with control group, 27 metabolites were down-regulated and 46 metabolites were up-regulated in plasma of FML group, and mainly enriched in metabolic pathways such as histidine metabolism, β-alanine metabolism, glycine, serine and threonine metabolism, phenylalanine metabolism, and linoleic acid metabolism. 2) Compared with control group, 23 metabolites were down-regulated and 24 metabolites were up-regulated in liver of FML group, and mainly enriched in metabolic pathways such as pantothenic acid and coenzyme A biosynthesis, β-alanine metabolism, nicotinate and nicotinamide metabolism, alanine, aspartate, and glutamate metabolism. 3) There were 10 differential metabolites with the same changes in plasma and liver. N-acetyltryptophan, N-methylisoleucine, 2-hydroxyhippuric acid, tetradecanedioic acid, FA 17∶0, kaempferol, and (R)-equol were upregulated, and D-fructose, 16-hydroxyhexadecanoic acid, and 3-hydroxy-3-methylglutaric acid were down-regulated. In conclusion, dietary supplemented with FML can alter the plasma and liver metabonomics of finishing pigs.

This experiment was conducted to investigate the effects of feeding levels of solid feed on rumen morphology and function of yak calves based on metabolomics analysis. Twenty-one 60-day-old weaned yak calves (male ) with similar body weight [(54.20±3.28 ) kg] were selected and divided into 3 groups with 7 calves in each group, namely high feeding level group (ad libitum feeding group, AL group), medium feeding level group (70 % feeding group, IR70 group) and low feeding level group (40 % feeding group, IR40 group). The pre-trial period was 30 days and the trial period was 90 days. The results showed as follows: 1) the thickness of mucosal epithelial, submucosal layer and muscular layer of rumen in AL group were significantly higher than those in IR70 group (P<0.05); the thickness of mucosal epithelial and muscular layer of rumen in AL group were significantly higher than those in IR40 group (P<0.05). The papillary length and muscular layer thickness of rumen in IR70 group were significantly higher than those in IR40 group (P<0.05). The rumen submucous layer thickness in IR40 group was significantly higher than that in IR70 group (P<0.05). 2) The rumen cellulase activity in IR70 group was significantly higher than that in AL group (P<0.05); the rumen cellulase activity in IR40 group was significantly higher than that in AL group (P<0.05). 3) Metabolomics analysis showed that compared with AL, the content of L-kynurenine in the metabolic pathway of African trypanosomiasis in IR40 group was significantly increased (P<0.05). Compared with AL group, the contents of differential metabolites L-asparagine and methionine in IR70 group were significantly decreased in carbon metabolism, mineral absorption and protein digestion and absorption pathways in cancer (P<0.05). In the protein digestion and absorption pathway, the content of the differential metabolite cadaverine decreased significantly (P<0.05); in the biosynthetic pathway of primary bile acids, the content of bile acids, a differential metabolite, increased significantly (P<0.05). In summary, when the yak calves are weaned at 60 days of age, and the ‘milk replacer+alfalfa hay+starter’ feeding method is used for early cultivation, increasing the level of solid feed feeding can promote the better development of rumen tissue morphology. Through metabolomics, it is found that the high feeding level improves the digestion and absorption of nutrients in yak calves, thereby improving the growth and development quality of yak calves, and providing an important basis for the scientific supplementary feeding of solid feed for lactating yak calves.

This experiment was conducted to study the correlation analysis of gut microbiota and plasma metabolites with average daily gain (ADG) of Tan sheep. A total of 156 male Tan lambs with similar body weights were selected and fed using the neck clamp method for 75 days, including a transition period of 15 days, a pre-test period of 10 days, and a trial period of 50 days. After the end of the trial period, the sheep with ADG>mean+0.5 times standard deviation was divided into the high ADG group (HADG group), and the sheep with ADG<mean+0.5 times standard deviation was divided into the low ADG group (LADG group), compared the differences of gut microbiota and plasma metabolites of Tan sheep between two groups (5 sheep in each group), and conducted the correlation analysis. The results showed as follows: 1) at the genus level, the relative abundances of Colidextribacter, Caproiciproducens, norank_f_norank_o_Veillonellales-Selenomonadales, Faecalibacterium and Enterorhabdus in cecum of HADG group were significantly higher than those of LADG group (P<0.05), and the Desulfovibrio relative abundance was significantly lower than that of LADG group (P<0.05); the relative abundances of Alloprevotella and Paludicola in rectum of HADG group were significantly higher than those of LADG group (P<0.05), and the Anaeroplasma and Faecalitalea relative abundances were significantly lower than those of LADG group (P<0.05). 2) The plasma metabolomics analysis identified 104 differential metabolites, compared to HADG group, 53 metabolites were down-regulated and 51 metabolites were up-regulated in LADG group. These metabolites were significantly enriched in pathways such as lysine biosynthesis, phenylalanine metabolism and glycolysis/gluconeogenesis (P<0.05). The plasma differential metabolites such as C20 sulfatide, palmitoleic acid, L-lactic acid, hydrocinnamic acid, and L-lysine were selected for correlation analysis with gut differential microbiota, the results showed that Desulfovibrio in cecum was significantly positively correlated with L-lactic acid and palmitoleic acid (P<0.05 or P<0.01), and norank_f_norank_o_Veillonellales-Selenomonadales was significantly negatively correlated with L-lactic acid (P<0.05); the Anaeroplasma in rectum was significantly positively correlated with L-lactic acid, C20 sulfatide and palmitoleic acid (P<0.05); the Faecalibacterium in rectum was significantly positively correlated with L-lactic acid and C20 sulfatide (P<0.05 or P<0.01), and significantly negatively correlated with L-lysine (P<0.05). In conclusion, the gut microbiota of Tan sheep influences ADG through plasma metabolites.

This experiment aimed to deeply explore the response mechanism of juvenile Onychostoma sima under starvation stress and reveal the dynamic changes at genetic and metabolic levels. Onychostoma sima [12 months of age, average body weight: (36.52±2.31) g] were subjected to a 14-day starvation stress experiment, with a control group (normal feeding) and a starvation group (continuously fasted for 14 days). After the starvation stress experiment, liver samples from both groups were analyzed using high-throughput sequencing and ultra-high-performance liquid chromatography (UHPLC) technologies for integrated transcriptomic and metabolomic profiling. Results: integrated analysis revealed that multiple key metabolic pathways were closely associated with the coordinated involvement of both differentially expressed genes (DEGs) and differentially expressed metabolites (DEMs). Among them, metabolic pathways, biosynthesis of secondary metabolites and thermogenesis were the three most prominent KEGG pathways jointly influenced by DEGs and DEMs. Further analysis showed that DEGs and DEMs were significantly enriched in the thermogenesis and cyanoamino acid metabolism pathways. Onychostoma sima upregulated the expression of thermogenesis-related genes by activating the adenylate cyclase (AC)-cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA) signaling pathway to promote heat production and maintain energy balance. Simultaneously, the enhancement of cyanoamino acid metabolism provided an additional energy source to sustain normal physiological activities. Thus, starvation stress significantly alteres the metabolic pathways in the liver of juvenile Onychostoma sima, thereby affecting its nutritional regulation mechanisms to adapt to physiological demands and environmental changes under starvation conditions. This study not only helps to understand the mechanisms of starvation stress affecting the liver function, but also provides valuable reference to optimizing feeding strategies for this species.

This study aimed to explore methods for the primary culture and identification of intestinal epithelial cells from orange-spotted grouper (Epinephelus coioides). Using intestinal tissue from E. coioides as experimental material, cells were cultured via tissue explant method and enzymatic digestion method, respectively, to compare the efficacy of these two culture methods. Different enzymatic treatments—trypsin, collagenase Ⅰ, and a combination of collagenase Ⅰ+collagenase Ⅳ, were applied to digest intestinal tissue and to compare their effectiveness in cell isolation. Three culture medias (DMEM, DMEM/F12, and L15 culture media) and varying concentrations (5%, 12% and 20%) of fetal bovine serum (FBS) were evaluated to compare their effects on cell growth. The cultured primary cells were characterized using morphological observation, transmission electron microscopy (TEM) observation, alkaline phosphatase (AKP) staining, 18S rRNA gene sequence alignment, and detection of intestinal cell-specific marker gene expression. Results showed that both enzymatic digestion method and tissue explant method yielded adherent cells. However, cell confluence on the flask bottom was observed at 12 days using the enzyme digestion method, whereas the tissue explant method took 28 days. Optimal digestion was achieved using 0.25 mg/mL trypsin supplemented with 0.91 mmol/L ethylenediaminetetraacetic acid (EDTA) for 15 min; this condition yielded sufficient cells while maintaining cell integrity and viability. Cells exhibited higher proliferation rate in L15 culture medium supplemented with 20% FBS. Characterization by TEM observation, AKP staining, and detection of intestinal cell-specific marker gene expression confirmed the cultured cells as intestinal epithelial cells. 18S rRNA gene sequence alignment verified the its grouper origin. Therefore, digesting the intestinal tissue of orange-spotted grouper with 0.25 mg/mL trypsin (containing 0.91 mmol/L EDTA) for 15 min, followed by culture of the isolated cells in L15 culture medium supplemented with 20% FBS, using above method can effectively obtain stably adherent primary intestinal epithelial cells from orange-spotted grouper.

Accurate assessment of nutrient requirements for pigs and realization of precise nutrition formulation are of great significance for improving feed resource utilization efficiency and promoting the development of the pig farming industry in China. This study aimed to construct a prediction model of the nutritional requirements for growing-finishing pigs based on classification algorithms by mining and analyzing existing literature data, and to identify the optimal model, thereby exploring the feasibility of classification algorithms in establishing more scientific and rational pig feeding standards. Literature published in the past decade regarding energy and amino acid requirements of “Duroc×Landrace×Yorkshire” pigs was systematically retrieved from the Web of Science database. Studies containing complete dietary nutrient levels and growth performance data were screened and compiled to form an initial dataset. Seventy-five percent of the initial dataset was allocated as the training dataset, and the remaining 25% as the validation dataset. Three machine learning algorithms-decision tree (DT), artificial neural network (ANN) and k-nearest neighbor (KNN)-were used to construct classification models. The results showed that the classification model based on the KNN algorithm performed best in predicting the nutrient requirements of growing-finishing pigs [with k=4, the misclassification rate (MCR) in the validation dataset was 0.374]. The KNN algorithm can be successfully applied to construct a classification model for predicting the nutrient requirements of “Duroc×Landrace×Yorkshire” growing-finishing pigs, providing foundational support for establishing more scientific pig feeding standards and precision feeding technologies.

In this experiment, Box-Behnken response surface method was used to optimize the steam explosion process parameters of flaxseeds. The dried flaxseeds were ground into powder as the substrate for steam explosion treatment. Initially, using protein solubility as the evaluation index, single-factor experiments were conducted to optimize the moisture content, pressure, and maintenance pressure time in the steam explosion process. The tested parameters were set as follows: moisture content, 17%, 19%, 21%, 23% and 25%, respectively; pressure, 0.4, 0.5, 0.6, 0.7 and 0.8 MPa, respectively; maintenance pressure time, 20, 40, 60, 80 and 100 s, respectively. Based on the results of the single-factor experiments, with moisture content, pressure and maintenance pressure time as independent variables, and protein solubility as the response value, the three steam explosion parameters of moisture content, pressure and maintenance pressure time were optimized through the Box-Behnken response surface test, and a regression model was established and verified. The results showed as follows: 1) the effects of moisture content and pressure on protein solubility were extremely significant (P<0.01), and the pressure maintenance time had a significant impact on protein solubility (P<0.05). The interaction between moisture content and pressure extremely significantly affected protein solubility (P<0.01). 2) The optimal steam explosion process parameters for flaxseeds were a moisture content of 23.11%, a pressure of 0.65 MPa, and a maintaining pressure time of 57.52 s. Under these conditions, the predicted protein solubility of flaxseeds was 79.05%, the verified value was 79.35%, and the error was less than 0.4%. 3) The crude protein content of flaxseeds showed no significant change before and after steam explosion, both being approximately 24%. Steam explosion treatment increased the protein solubility of flaxseeds from 69.00% to 79.35%, an increase of approximately 10%. 4) Analysis of the secondary structure of the protein revealed that the proportion of α-helix decreased and the proportion of β-sheet and random coil increased after steam explosion, indicating that steam explosion transformed the secondary structure of flaxseed protein from ordered to disordered. The response surface method can effectively optimize the steam explosion process parameters of flaxseeds. Steam explosion treatment can improve the protein solubility of flaxseeds, and the mechanism is closely related to the reduction of the orderliness of the protein secondary structure.

This experiment was conducted to investigate the effects of compound microecological preparations on rumen fermentation gas production, fermentation parameters and nutrient degradation rates of dairy cows in vitro. A single-factor experimental design was adopted, and it was divided into 4 groups, which were supplemented with 0 (control group, CK group), 0.4 (T1 group), 0.8 (T2 group) and 1.2 g/kg (T3 group) compound microecological preparations [inactivated Lactobacillus acidophilus≥10⁷ CFU/g, Bacillus subtilis≥10⁷ CFU/g, and Aspergillus oryzae (counted by spores)≥10⁷ CFU/g] in the total mixed ration (TMR) substrate, respectively. Each group had 6 replicates and was cultured in vitro for 48 h. The results showed as follows: 1) the gas production in T2 group was the highest among all groups after 2 h, and it was significantly higher than that in CK group from 12 to 48 h (P<0.05). With the increase of the supplemental level of compound microecological preparations, the rumen gas production showed a quadratic change of first increasing and then decreasing from 4 to 48 h (P<0.05). 2) Compared with CK group, the ammonia nitrogen concentration in the compound microecological preparation supplemental groups was significantly decreased (P<0.05), with the lowest in T2 group; the concentrations of acetic acid, valeric acid and total volatile fatty acid in T2 group were significantly increased (P<0.05). 3) The dry matter degradation rate in T2 group was significantly higher than that in T1 group (P<0.05), and the starch degradation rate in T3 group was significantly higher than that in T1 group (P<0.05). There was no significant difference in the degradation rates of neutral detergent fiber and acid detergent fiber among all groups (P>0.05). 4) The amylase activity in T2 group and T3 group was significantly higher than that in T1 group (P<0.05), and the microbial protein concentration was significantly higher than that in CK group and T1 group (P<0.05). In conclusion, the compound microecological preparations can improve the rumen fermentation of dairy cows in vitro, with an appropriate supplemental level of 0.8 to 1.2 g/kg.

This study aimed to investigate the effects of different silage additives [Lactobacillus plantarum (LP), Lactobacillus brucei (LB), Bacillus subtilis (BS), molasses (M)] on fermentation quality, nutrient composition, and number of microbial colonies of mulberry branches and leaves silage. The experiment was divided into control (CON) group (without any additives), LP group (2.0 g/t LP), LB group (2.0 g/t LB), LP+BS group (1.0 g/t LP and 1.0 g/t BS) and LP+LB+BS+M group (0.5 g/t LP and 0.5 g/t BS) LB, 1.0 g/t BS and 0.3% M), five replicates per group. At room temperature, after 60 days of fermentation, samples were opened and taken for index analysis. The results indicated that compared with the CON group, the number of lactic acid bacteria (LAB) and the content of lactic acid (LA) in the additive groups increased significantly (P<0.05), while the pH, ammonia nitrogen (NH₃-N) and ethanol contents and the number of yeast decreased significantly (P<0.05). Among them, LP+LB+BS+M group had the highest LAB quantity, LA, acetic acid (AA) content and LA/AA ratio, and the lowest pH, propionic acid (PA), ethanol, NH₃-N content and yeast number, and the number of Escherichia coli and mold were below the detection limit [<2.00 lg(CFU/g)]. Butyric acid was not detected in any of the samples. The contents of dry matter (DM) and crude fat (EE) did not change significantly in all groups (P>0.05). Compared with CON group, the content of crude protein (CP) in LP+LB+BS+M group was significantly increased (P<0.05). The content of neutral detergent fiber (NDF) in LB, LP+BS and LP+LB+BS+M groups was significantly decreased (P<0.05). The content of acid detergent fiber (ADF) in LP, LP+BS and LP+LB+BS+M groups was significantly decreased (P<0.05). The content of water-soluble carbohydrate (WSC) in LP+LB+BS+M group was significantly increased (P<0.05), and the content of WSC in LP+BS group was significantly lower than that in CON group (P<0.05). The content of total flavonoids (TF) in LP, LP+BS and LP+LB+BS+M groups was significantly increased (P<0.05). In conclusion, the addition of LP+LB+BS+M can improve the quality of mulberry branches and leaves silage and release more flavonoid active substances.

This study aimed to investigate the effects of steam explosion treatment for red clover on extraction efficiency of isoflavone. A three-factor, three-level response surface methodology was employed, with the factors affecting the extraction efficiency of isoflavone of explosion pressure, treatment time and moisture content, and the red clover isoflavone yield as the response variable, and the optimal steam explosion treatment conditions were determined using heat reflux extraction technology. The results showed as follows: 1) the optimal steam explosion treatment conditions for isoflavone extraction from red clover were explosion pressure of 0.6 MPa, treatment time of 150 s, and moisture content of 40%. Under these conditions, the red clover isoflavone yield was 93.71%, the red clover isoflavone yield was increased by 62.55% compared with no steam explosion treatment. 2) Scanning electron microscopy analysis showed that the significant structural disruption of red clover after steam explosion treatment, resulting in a loose and disordered structure, which exposed internal pores and increased surface area, thereby enhancing isoflavone extraction. In conclusion, the steam explosion treatment can enhance the extraction efficiency of red clover isoflavone, and can providing reference for the industrial production of red clover isoflavone as feed additives.

This experiment aimed to explore the relationship between the natural grassland and the balance of grassland and livestock, in order to provide references for the management of the balance of alpine meadow grassland and livestock. The typical Kobresia a grassland in Sanjiangyuan region was taken as the research object, the edible forage, crude protein and metabolic energy output per unit grassland area were analyzed by monitoring forage biomass of four different periods (hay stage, regreening stage, grassy stage and withering stage) and using in vitro fermentation method combined with conventional nutritional analysis method, meanwhile, the carrying capacity of edible forage, digestible crude protein and metabolic energy were calculated. The results showed as follow: the yield of edible forage in alpine meadow of typical Kobresia grassland during hay stage, regreening stage, grassy stage and withering stage were 64.14, 32.22, 174.47 and 98.15 g/m², the carrying capacity of edible forage were 1.06, 2.24, 6.49 and 5.17 SHU/hm², and the output of crude protein per grassland unit area were 2.35, 4.76, 20.78 and 5.18 g/m². When the feeding objectives of grazing livestock were maintain demand, normal growth demand and high-quality production demand, the carrying capacity of digestible crude protein were 0.72, 6.87, 16.01 and 5.05 SHU/hm², 0.46, 4.43, 10.33 and 3.26 SHU/hm², and 0.40, 3.87, 9.02 and 2.85 SHU/hm². The output of metabolic energy per grassland unit area during hay stage, regreening stage, grassy stage and withering stage were 0.28, 0.28, 1.53 and 0.71 MJ/m². When the feeding objectives of grazing livestock were maintain demand, normal growth demand and high-quality production demand, the carrying capacity of metabolic energy were 1.04, 3.12, 9.03 and 8.44 SHU/hm², 0.70, 2.08, 6.03 and 5.63 SHU/hm², and 0.61, 1.83, 5.32 and 4.79 SHU/hm². According to the carrying capacity of digestible crude protein, 1.05 to 10.96 SHU/hm², 2.84 to 12.75 SHU/hm² and 3.25 to 13.16 SHU/hm² stock reduction should be reduced at the end of the grassy stage, which were 17.21% to 68.46%, 46.56% to 79.64% and 53.28% to 82.20% stock reduction. In conclusion, it is recommended to dynamically regulate grazing intensity based on phenological stages, establish a rotational grazing system aligned with the nutritional dynamics of forage grass, efficiently utilize high-quality pasture during the green growth period, supplement feed or restrict stocking rates during the dormant season, thereby achieving seasonal forage-livestock balance and ensuring sustainable utilization of grassland resources.

This experiment was conducted to evaluate the metabolizable energy of 10 kinds of rapeseed meals from different sources in Xiangjia yellow chicken No.2, and to establish a prediction model for the metabolizable energy of rapeseed meals in fast-growing yellow-feathered broilers based on the chemical components in rapeseed meals. The experiment was divided into two stages, with the first stage being 14 to 18 days of age and the second stage being 35 to 39 days of age. In the first stage, 528 fourteen-day-old male Xiangjia yellow chicken No.2 with an initial body weight of (273±2) g were selected and randomly divided into 11 groups, with 6 replicates in each group and 8 chickens in each replicate. In the second stage, another 264 thirty-five-day-old male Xiangjia yellow chicken No.2 with an initial weight of (1 256±5) g were selected and randomly divided into 11 groups, with 6 replicates in each group and 4 chickens in each replicate. Each group was fed 10 kinds of rapeseed meal diets and 1 kind of basal diet, respectively. Among them, the rapeseed meal diets adopted the proportional substitution method, using 10 kinds of rapeseed meals from different sources to replace 20% of the energy supply components in the basal diet. Each stage consisted of a 2-day pre-test period and a 3-day fecal collection period, and the excrement was collected by the full fecal collection method. The results showed as follows: 1) there were differences in the common nutrient contents of rapeseed meals from different sources. 2) The source of rapeseed meals had a significant effect on apparent metabolizable energy (AME) and nitrogen corrected apparent metabolizable energy (AMEn) (P<0.05). The average values of AME and AMEn of 10 kinds of rapeseed meals in fast-growing yellow-feathered broilers were 8.36 and 7.67 MJ/kg from 14 to 18 days of age, and 8.03 and 7.15 MJ/kg from 35 to 39 days of age, respectively. 3) Based on the stepwise regression analysis, it was concluded that the AME and AMEn prediction equations for rapeseed meals in fast-growing yellow-feathered broilers were AME=28.890+0.317×ether extract (EE)-0.603×crude fiber (CF)-4.567×acid soluble protein (ASP) [determination coefficient (R²)=0.576, P<0.001], AMEn=27.569+0.315×EE-0.672×CF-3.911×ASP (R²=0.621, P<0.001) from 14 to 18 days of age; AME=30.373+0.617×EE-6.522×ASP-0.928×crude ash (Ash) (R²=0.662, P<0.001), AMEn=26.023+0.582×EE-5.961×ASP-0.647×Ash (R²=0.616, P<0.001) from 35 to 39 days of age, respectively. This study provides data references for evaluating the nutritional value of rapeseed meal and enriching the database of feed ingredients for yellow-feathered broilers in China.

The purpose of this experiment was to evaluate the metabolic energy of Zanthoxylum bungeanum leaves (ZBL) in broilers, and to study the effects of dietary ZBL on the growth performance, serum biochemical indicators, intestinal mucosal morphological structure and cecal microbial community of Daheng broilers. Metabolism experiment: the metabolizable energy was determined using a substitution method combined with the indicator method. Forty-eight healthy 42-day-old male yellow-feathered broilers with similar body weight were randomly divided into 2 groups (8 replicates per group, 3 chickens per replicate, 1 chicken/cage) and fed a basal diet and an experimental diet (85% basal diet+15% ZBL), respectively. The experiment lasted for 7 days, including a 4-day pre-test period and a 3-day formal test period. Feeding experiment: three hundred and eighty-four healthy Daheng broiler roosters with similar body weight at 50 days of age were selected and randomly divided into 4 groups (8 replicates in each group, 12 chickens in each replicate), and the control group was fed a basal diet, while the experimental groups were provided with experimental diets supplemented with 2% (ZBL Ⅰ group), 3% (ZBL Ⅱ group) and 4% (ZBL Ⅲ group) ZBL, respectively. The experimental period was 37 days. The results showed as follows: 1) the metabolizable energy of ZBL for broilers was 5.87 MJ/kg, and the apparent digestibility of energy was 34.14%. 2) Compared with the control group, adding 2%, 3% and 4% of ZBL to the diet could extremely significantly increase the feed to gain ratio (F/G) of Daheng broilers (P<0.01), and adding 4% of ZBL to the diet also could significantly reduce the final body weight and average daily gain of Daheng broilers (P<0.05). However, ZBL supplemental level had no significant effects on average daily feed intake, slaughter performance and organ indices (P>0.05). 3) Compared with the control group, adding 3% of ZBL to the diet significantly increased serum albumin (ALB) content (P<0.05), and adding 2%, 3% and 4% of ZBL to the diet significantly reduced serum urea content (P<0.05). 4) Dietary with different supplemental levels of ZBL did not significantly affect intestinal mucosal morphological structure (P>0.05). 5) Compared with the control group, adding 4% of ZBL to the diet significantly increased cecal microbial richness (Chao index) and diversity (Shannon and Simpson indices) (P<0.05); LEfSe analysis revealed significant enrichment of Methanobrevibacter and Odoribacter in the ZBL Ⅱ group compared with the ZBL Ⅲ group. In summary, the metabolic energy of ZBL in broilers is 5.87 MJ/kg; although adding 2% to 4% of ZBL leaves to the diet has a negative impact on the feed conversion rate of Daheng broilers, the appropriate addition does not have a significant effect on their final body weight, slaughter performance and organ indexes, and it improves the richness and diversity of the cecal microbiota. Therefore, ZBL can be used as feed raw materials for Daheng broilers, but the addition amount should not exceed 3%.

This experiment aimed to investigate the effects of different additives on nutritional quality, fermentation quality, microbial diversity, in vitro fermentation parameters, and nutrient digestibility of natural pasture silage. The experiment used natural grass as ensiling material, using single factor randomized block design, set up 6 groups, namely control group (CK group, no addition), formic acid (FA) group (6 mL/kg FA), cellulase (CE) group (0.2 g/kg CE), fermented green juice (FGJ) group (2 mL/kg FGJ), Astragalus polysaccharide (APS) group (0.5% APS), APS+FGJ (H) group (0.5% APS and 2 mL/kg FGJ), five replicates in each group. After 60 days of silage, the nutritional quality, fermentation quality, microbial diversity, in vitro fermentation parameters and nutrient digestibility of silage were analyzed, and the membership function method was used for comprehensive evaluation. The results showed as follows: 1) compared with CK group, dry matter (DM) and crude protein (CP) contents in each group significantly increased (P<0.05) while reducing propanoic acid (PA) content (P<0.05); the lactic acid (LA) content in H group significantly increased (P<0.05) and pH, neutral detergent fiber (NDF), and acid detergent fiber (ADF) contents significantly decreased (P<0.05). 2) Firmicutes was the dominant phylum in all groups. Compared with CK group, the relative abundance of Pediococcus in FGJ and H groups was higher, which was 53.03% and 41.95%, respectively. 3) After 48 h of in vitro fermentation, in vitro dry matter digestibility (IVDMD), in vitro NDF digestibility (IVNDFD), and total volatile fatty acid (TVFA) content in each group significantly increased (P<0.05), while reducing NH₃-N content in rumen fluid (P<0.05). The H group achieved the highest IVDMD and IVNDFD. Except for FA, all groups significantly decreased the acetic acid/propionic acid (AA/PA) (P<0.05). 4) The subordinate function evaluation ranked the highest in H group, with a score of 0.75. In conclusion, all five additives improve the nutritional quality, fermentation quality, microbial diversity, in vitro fermentation parameters, and nutrient digestibility of natural pasture silage. The combined application of APS and FGJ has the optimal ensiling performance.

This experiment aimed to investigate the effects of adding lactic acid bacteria on the silage fermentation quality and selenium content of flood-stricken selenium-enriched rice. A three-factor randomized experimental design was adopted. Factor 1 was whether the flood-stricken rice was selenium-enriched, with two levels: flood-stricken common rice and flood-stricken selenium-enriched rice. Factor 2 was whether lactic acid bacteria were added, with two levels: no addition and addition of Lactobacillus plantarum AS98 (1×10⁷ CFU/mL). Factor 3 was the fermentation time, with seven levels: 1, 3, 5, 7, 15, 30, and 45 days. Four treatments were set up: flood-stricken common rice, flood-stricken common rice+Lactobacillus plantarum AS98, flood-stricken selenium-enriched rice, and flood-stricken selenium-enriched rice+Lactobacillus plantarum AS98. Samples from each treatment were fermented separately, and samples were taken at 1, 3, 5, 7, 15, 30, and 45 days of fermentation to determine the nutritional components, fermentation quality, and organic selenium, inorganic selenium, and total selenium contents of the silage. Three replicates were set up for each group. The results showed that the fermentation quality of flood-stricken selenium-enriched rice silage was higher than that of flood-stricken common rice silage, and the total selenium, organic selenium and inorganic selenium contents were significantly higher than those of flood-stricken common rice silage (P<0.05). With the increase of fermentation days, the pH, dry matter, crude protein, organic matter, neutral detergent fiber, soluble carbohydrate contents and Escherichia coli number in each group decreased significantly (P<0.05), the crude fat content gradually increased (P<0.05), and the number of lactic acid bacteria and lactic acid content increased significantly (P<0.05). After adding Lactobacillus plantarum AS98, the total selenium, organic selenium and inorganic selenium contents of flood-stricken selenium-enriched rice silage increased significantly (P<0.05), reaching 247.91, 232.71 and 15.21 μg/kg, respectively. The addition of lactic acid bacteria effectively reduced the pH of silage, and the pH of flood-stricken common rice and flood-stricken selenium-enriched rice silage decreased to 4.10 and 4.15, respectively. The number of lactic acid bacteria increased significantly (P<0.05), the number of Escherichia coli decreased significantly (P<0.05), and the lactic acid content increased to 6.05 and 7.09 g/kg FM, respectively. The growth of undesirable microorganisms was inhibited, the loss of nutrients was reduced, and the preservation and nutritional value of silage were improved. In conclusion, the addition of Lactobacillus plantarum AS98 can significantly improve the silage quality and selenium preservation of flood-stricken selenium-enriched rice.

The study was designed to optimize the solid-state fermentation process of Portulaca oleracea L. by Aspergillus oryzae. The fermentation time, water content and inoculation amount were selected as influencing factors. With the contents of polysaccharide and flavonoid from Portulaca oleracea L. as evaluation indicators, the solid-state fermentation process was optimized using the single factor analysis and response surface method, and the antioxidant activity of Portulaca oleracea L. before and after fermentation was determined. The results showed that the optimal fermentation process for Portulaca oleracea L. was a fermentation time of 6.3 days, a water content of 85.2%, and an inoculation amount of 6.2%, with the polysaccharide content was 2.23 mg/mL and the flavonoid content was 442 μg/mL after fermentation. Portulaca oleracea L. before and after fermentation showed an ability to scavenge 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals. The half-maximal inhibitory concentration (IC₅₀) of Portulaca oleracea L. and fermented Portulaca oleracea L. for ABTS free radical was 0.531 and 0.455 mg/mL, and for DPPH free radical was 2.155 and 1.387 mg/mL, respectively. Therefore, Portulaca oleracea L. fermented by Aspergillus oryzae has higher antioxidant activity.

This experiment aimed to study the solid-state fermentation conditions of Phanerochaete chrysosporium fermenting peeled bagasse. The experiment used a four factors and three levels orthogonal experimental design, four factors were Phanerochaete chrysosporium addition amount (1%, 3% and 5%), fermentation time (15, 30 and 45 d), sucrose addition amount (1%, 3% and 5%) and initial pH (4, 5 and 6), with three levels in each factor, and a total of 9 groups (group A to group I), to solid-state closed fermentation. The results showed as follows: 1) the contents of neutral detergent fiber (NDF) and hemicellulose (HC) in fermented peeled bagasse of group F were significantly lower than those of other groups (P<0.05), the content of acid detergent fiber (ADF) in fermented peeled bagasse of groups E and G was significantly lower than that of other groups (P<0.05), the content of cellulose (CL) in fermented peeled bagasse of group I was significantly lower than that of groups B, D, F and H (P<0.05), and the content of acid detergent lignin (ADL) in fermented peeled bagasse of group E was significantly lower than that of groups C, D, G, H and I (P<0.05). 2) The content of ammonia nitrogen (NH₃-N) in fermented peeled bagasse of group F was significantly lower than that of other groups (P<0.05), the content of lactic acid (LA) in fermented peeled bagasse of group I was significantly higher than that of other groups (P<0.05), the fermented peeled bagasse pH of group E was significantly lower than that of other groups (P<0.05), and the content of butyric acid (BA) in fermented peeled bagasse was no detected in groups A, E and F. 3) The microbial Shannon index of group B was significantly higher than that of group E (P<0.05), and the Simpson index was significantly higher than that of groups E and H (P<0.05). At the phylum level, the Bacillota relative abundance showed group B>group E>group H; at the genus level, the Liquorilactobacillus relative abundance showed group E>group B>group H; at the species level, the Bacillus pumilus relative abundance showed group E>group H>group B. In conclusion, the orthogonal analysis results and comprehensive scoring showed that the 3% Phanerochaete chrysosporium addition amount, 45 d fermentation time, 5% sucrose addition amount and 4 initial pH are the optimal fermentation conditions for the fermentation of peeled bagasse fermented by Phanerochaete chrysosporium. Under these conditions, the nutritional value, fermentation quality and the relative abundance of beneficial bacteria of the solid-state fermentation of peeled bagasse are the best.

This study utilized complex probiotics to ferment the prawn processing by-product (shrimp heads and shells), and determined the optimal process for preparing the fermentation liquid of prawn processing by-product. Through orthogonal test, the optimal mixing ratio of Lactobacillus acidophilus, Bacillus subtilis and Candida utilis were screened out among the complex probiotics; single-factor tests were carried out on the inoculation volume, initial pH, fermentation temperature, fermentation time, solid-liquid ratio, and glucose addition amount, respectively; then, based on the results of the single-factor tests, the inoculation volume, fermentation temperature and fermentation time were optimized by response surface method to determine the optimal process of fermentation of shrimp head shell waste with complex probiotics. The fermentation liquid of prawn processing by-product was mixed with compound feed in a 1∶1 ratio, and the changes in nutritional components were analyzed. The results showed as follows: 1) The optimal mixing ratio of Lactobacillus acidophilus, Bacillus subtilis and Candida utilis screened out by the orthogonal test was 2∶1∶2. 2) Through single factor test and response surface test, the optimal process of fermentation of prawn processing by-products was inoculation volume 16%, initial pH 6.5, temperature 38.5 ℃, fermentation for 48 h, solid-liquid ratio 1∶1.5, glucose addition amount 15%. 3) The protein recovery rate of fermentation liquid of prawn processing by-product was (94.7±0.3)%; after being mixed 1∶1 with compound feed, the crude protein content in the feed could be increased by 9.16%, and the total amount of 17 kinds of amino acids could be increased by 2.63%. The results of this study have reference value for enhancing the utilization value of prawn processing by-product and promoting their high-value processing.