In early studies, it was found that ruminants have a unique complex digestive and metabolic system, the abomasum and intestinal digesta empties are significantly different from those of monogastric animals. However, limited by research methods, few studies have been carried out on the composition of digesta, gastrointestinal digestive enzymes, microbial composition and the nutrients digestion in the rumen. In subsequent studies, the role of rumen in ruminants has been highly valued, while the role of other parts of digestive tract, especially the abomasum and intestines, in nutrients digestion and metabolism has been neglected for a long time. Since then, limited studies have shown that the digestive tract after the rumen may play a crucial role in nutrient metabolism, especially with the development of high-concentrate fattening technology for beef cattle, this importance is increasing. The author believes that taking the nutrient metabolism of different digestive parts of ruminants into consideration as a whole and establishing the whole digestive tract nutrient regulation theory will be more in line with the needs of ruminant nutrition research and will be more targeted to guide the production of ruminants. At present, the priority of research should be to explore the digestive tract nutrient metabolism of nutrients in the post-rumen digestive tract, and how different parts of the digestive tract cooperate to achieve nutrient digestion and metabolism.

The intestinal barrier is not only a structural basis for selective digestion and absorption of nutrients, but also a protective barrier for the intestinal tract to continuously receive external stimuli. Sodium butyrate can maintain the integrity of intestinal mucosal epithelium, enhance intestinal immune function, reduce intestinal inflammation and maintain intestinal microbiota balance by regulating histone acetylation, G protein-coupled receptor and other pathways, so as to play the role of disease resistance and growth promotion. This review summarized the mechanism of sodium butyrate regulating intestinal barrier and its application in broiler breeding, in order to provide references for sodium butyrate to replace antibiotics in broiler nutrition.

Vitamin B₆ is an essential micronutrient for the healthy growth and normal physiological function of animals. It not only participates in the normal metabolic reaction of the body as a coenzyme, but also has a variety of biological functions such as neuromodulation, antioxidant, anti-inflammatory, immunomodulatory and anti-tumor. Low plasma vitamin B₆ level status is strongly associated with higher risk of a variety of inflammatory disease. The inverse association is thought to be the result of mobilization of vitamin B₆ to the site of inflammation, for use of regulation of tryptophan and sphingolipid metabolism, modulation of lymphocyte trafficking, number and function, and inhibition of inflammatory signaling pathway, to exert their immunomodulatory and anti-inflammatory properties. This article reviewed the biological functions, potential anti-inflammatory mechanism and application in feed of vitamin B₆, in order to provide reference for the application of vitamin B₆ in animal husbandry.

Glucose is the main energy supplier for animals, and the metabolic dysfunction of glucose is closely related to the occurrence of metabolic diseases, including obesity and type Ⅱ diabetes. The concentrations of some glucose metabolic intermediates, such as succinate, L-malic acid, α-ketoglutarate and lactate can reflect the health status, and also influence the biological processes related to growth rate and meat quality traits formation of livestock and poultry, including muscle fiber type conversion and fat deposition, implying that glucose metabolic intermediates are of application prospects in the efficient and high-quality production of meat. Therefore, in this review, the relationship between glucose metabolic disturbance and the occurrence of metabolic diseases were introduced, and the beneficial effects of succinate, L-malic acid and α-ketoglutarate intake at different physiological stages were analyzed. Furthermore, the role of glucose metabolic intermediates in improving growth performance, carcass quality and meat quality of pigs were reviewed, which will provide a basis for improving the quality and efficiency of pig production.

With the intensive production of livestock and poultry and the enhancement of people’s health awareness, consumers are more and more concerned about the quality and nutritional value of livestock and poultry muscle, such as shear force, drip loss, cooking loss, pH value, intramuscular fat content. Nicotinic acid (NA) is an essential vitamin for animal body to fully synthesize nicotinamide adenine dinucleotide (NAD). It has a variety of biological functions such as antioxidant, lipid metabolism regulation, muscle fiber type conversion promotion, and animal growth performance improvement. This article reviews the effects and possible mechanisms of nicotinic acid in regulating meat quality of livestock and poultry, focusing on the possible mechanisms of nicotinic acid improving meat quality, in order to provide theoretical reference for the application of nicotinic acid in improving meat quality in livestock and poultry production.

The problem of drug resistance of pathogenic microorganisms and drug residues in livestock and poultry products caused by long-term feeding antibiotics is becoming more and more serious. Low-molecular-weight organic acid (LOA) has a variety of disease resistant and nutritional functions, such as anti-bacterial, immune regulation and growth promotion, and is an important acidifier to replace antibiotics. In this paper, the nutritional characteristics, disease resistant functions, mechanisms and measures for improving disease resistant and nutritional efficacy of LOA were reviewed in order to provide reference for further research of its disease resistant nutritional functions.

Inulin is a fructosan type plant polysaccharide widely existing in nature, and it has many biological functions, such as promoting the absorbing of minerals, promoting glucose and lipid metabolism, anti-oxidation, prebiotic effect and so on. This article reviewed the extraction process and biological functions of inulin and its application in ruminant production, aiming to provide theoretical reference for the application of inulin in ruminants.

Lactose is one of the main nutrients in milk and plays an important role in regulating milk production in dairy cows. This paper reviews lactose synthesis from the mammary gland structure, lactose synthesis substrate, lactose synthesis regulation and lactose secretion in dairy cows; systematically elucidates the biological theory of lactose in regulating milk production by maintaining vesicular osmotic pressure. We also analyzed the relationship between lactose content and milk yield, milk protein and milk fat contents in different lactating animals to reveal the biological function of lactose in regulating milk production, and to provide a theoretical basis and potential targets for improving milk production performance.

There are various types of ureolytic bacteria in ruminants. Exploring the composition of ureolytic bacteria and understanding the activation mode of urease in rumen can provide a basis for slowing down urea decomposition rate and improving urea utilization efficiency. The paper reviews the diversity of rumen ureolytic bacteria on the gene level, mRNA level and protein level, respectively, and the activation pattern of auxiliary proteins in rumen high abundance urease, so as to provide a reference for understanding the process of urea hydrolysis in the rumen and developing targeted urease inhibitors.

As one of the components of milk, milk-derived exosomes can carry and transmit important signaling molecules, thus mediating mother-child or interspecific information exchange, regulating a variety of physiological and pathological processes of newborn animals, including promoting the absorption and metabolism of nutrients, and playing an important role in preventing and alleviating various intestinal diseases and inflammation. At the same time, they can also participate in immune system development, promote immune cell proliferation. However, some components of milk-derived exosomes also have some negative effects while working in nutrition and immune regulation. Therefore, it is important to fully understand the role of milk-derived exosomes for the high-quality development of animal husbandry and related industries. This article summarized the research progress of milk-derived exosomes in the regulation of nutrition and immune function and provided valuable reference for related research.

Selenium (Se) is an essential trace element for aquaculture animals, which plays an important role in maintaining normal growth, enhancing immune and antioxidant functions. However, the range of suitable Se inclusion in the diet is very narrow and excess Se will result in a variety of toxic effects in animals. In this paper, we reviewed the biological functions of Se in aquaculture animals and the toxic effects caused by excess Se and its related mechanisms. Moreover, the optimal requirements of Se in different forms in the diet for various aquaculture animals were also summarized in the paper. The aim of this paper is to provide a reference for nutritional studies of Se in aquaculture animals as well as for the accurate use of Se additives in production.

Epiphytic microorganisms mainly refer to foliar microorganisms of plants and are important factors affecting silage quality, at the same time, the species and composition of epiphytic microorganisms are affected by many factors. This review summarized the influence of external factors on the composition of epiphytic microorganisms of green forage and the influence of host source on the composition of epiphytic microorganisms of green forage and the quality of silage. The aim of this review is to elucidate the composition characteristics and influencing factors of epiphytic microorganisms of different green forage and their effects on silage quality, with the aim of providing a theoretical basis for rational utilization of beneficial epiphytic microorganisms and inhibition of harmful epiphytic microorganisms to improve the quality of silage.

The by-products of pepper are mainly composed of pepper straw and pepper meal, and the reserves are considerable, which can be used for livestock breeding feed. In this paper, the nutritional composition, the main active substances of pepper by-products and their feed-based applications in animal production were reviewed, in order to provide a theoretical reference for the reasonable and safe application of pepper by-products in diets of livestock and poultry.

This experiment was conducted to investigate the effects of different feeding time under restricted feeding conditions on carcass quality, meat quality and serum biochemical indices of finishing pigs. Thirty healthy three-way crossbred weaned piglets with similar body weight [(10.11±0.10) kg] were randomly divided into 3 groups (10 replicates in each group and 1 piglet in cah replicate): group A (feeding for 5 months), group B (feeding for 6 months) and group C (feeding for 7 months). The feed intake was controlled to 85% and 80% of group A, respectively, the 3 groups started at different time, when the average weight of experimental pigs in 3 groups reached 120 kg, slaughtered at the same time. The results showed that compared with the group A: 1) the average daily gain and average daily feed intake of groups B and C were significantly decreased (P<0.05), the carcass straight length was significantly increased (P<0.05); the backfat thickness of group B was significantly decreased (P<0.05); the longissimus dorsi redness (a^*) value at 45 min after slaughter of groups B and C was significantly increased (P<0.05), and the brightness (L^*) value was significantly decreased (P<0.05); 2) the serum urea nitrogen content of group B was significantly decreased (P<0.05), the contents of total protein, albumin, glucose, cholesterol, low density lipoprotein cholesterol and free fatty acid in serum of group C were significantly decreased (P<0.05), and the serum high-density lipoprotein cholesterol content of groups B and C was significantly increased (P<0.05); 3) the taste strength value of sweet amino acids, such as serine, glycine and arginine in longissimus dorsi of group B was significantly increased (P<0.05), and the taste strength value of bitter amino acid, such as phenylalanine in longissimus dorsi of groups B and C was significantly decreased (P<0.05); 4) the proportions of C18∶3n3 and C20∶2 in longissimus dorsi of group B were significantly increased (P<0.05), and the proportions of C18∶3n3, C20∶2, C22∶6n3 and total n-3 polyunsaturated fatty acids in longissimus dorsi of group C were significantly increased (P<0.05); 5) the glucose content and porcine hexokinase activity in longissimus dorsi of groups B and C were significantly increased (P<0.05), the glycolysis potential and glycogen content in longissimus dorsi of group C were significantly decreased (P<0.05), and the mRNA expression level of myosin heavy chain Ⅰ in longissimus dorsi of groups B and C was significantly increased (P<0.05). In conclusion, the longissimus dorsi fatty acid composition, muscle fiber type and meat quality of finishing pigs can be improved by extending the feeding time to 7 months under restricted feeding conditions, but the growth performance can be decreased, it increases the cost of making meat to some extent.

The aim of this study was to investigate the effects of dietary alfalfa processing dust on the growth performance, carcass traits, meat quality and economic efficiency of fattening pigs, and to explore its application effect on fattening pigs. Forty-eight “Duroc×Landrace×Yorkshire” ternary crossbred pigs with an average weight of (30.32±1.46) kg were selected and randomly divided into four groups with three replicates per group and four pigs per replicate according to the principle of gender and weight consistency. The control group was fed a basal diet, and the experimental groups were fed basal diets supplemental with 2%, 4% and 6% alfalfa processed dust, respectively. The trial period was 82 d, which divided into two stages: early fattening stage (1 to 41 d) and late fattening stage (42 to 82 d). The results showed as follows:1) compared with the control group, the average daily gain (ADG), average daily feed intake (ADFI) and feed to gain ratio (F/G) in late fattening stage and while fattening stage of 2% alfalfa processed dust group were no significant difference (P>0.05), the ADFI in early fattening stage was significantly decreased by 10.13%(P<0.05), and the ADG and F/G in early fattening stage were decreased by 6.85% and 3.53% (P>0.05); the ADG, ADFI and F/G in early fattening stage, late fattening stage and whole fattening stage of 4% and 6% alfalfa processed dust groups were no significant difference (P>0.05). 2) Compared with the control group, the lean meat percentage of 2%, 4% and 6% alfalfa processed dust groups was increased by 0.60%, 1.50% and 2.45% (P>0.05); there were no significant differences in live weight before slaughter, carcass weight, dressing percentage, eye muscle area, carcass straight length, carcass oblique length, bone percentage, skin percentage and fat meat percentage among all groups (P>0.05). 3) There were no significant differences in marbling score, water lose percentage, shear force, brightness value, redness value, yellowness value, cooked meat percentage among all groups (P>0.05). 4) Compared with the control group, in early fattening stage, the feed weight gain cost of 2% and 4% alfalfa processing dust groups was decreased by 0.48 and 0.65 RMB/kg (P>0.05), and the 6% alfalfa processing dust group was significantly decreased by 0.83 RMB/kg (P<0.05); in later fattening stage, the feed weight gain cost of 2%, 4% and 6% alfalfa processing dust groups was decreased by 0.03, 0.02 and 0.37 RMB/kg (P>0.05); in whole fattening stage, the feed weight gain cost of 2%, 4% and 6% alfalfa processing dust groups was decreased by 0.18, 0.36 and 0.57 RMB/kg (P>0.05). In summary, the dietary 2% to 6% alfalfa processing dust have no negative effects on the growth performance, carcass traits and meat quality of fattening pigs, and it can also improve the carcass lean percentage, the 6% alfalfa processing dust supplemental level can reduce feed cost in the maximum extent.

This experiment was conducted to investigate the effects of reducing dietary n-6/n-3 polyunsaturated fatty acid (PUFA) ratio with vegetable oil supplementation on fat deposition, fatty acid composition and the expression of genes involved in lipid metabolism of growing-finishing pigs. Fifty-four growing pigs (Duroc×Landrace×Yorkshire) at a live weight of (45.30±1.72) kg were randomly allocated to 3 groups with 6 replicates per group and 3 pigs per replicate. The control group was fed a basal diet, and the experimental groups were fed diets containing 4.5% rapeseed oil (rapeseed oil group) and 4.5% mixed oil (mixed oil group, rapeseed oil∶linseed oil=1∶1), respectively. The levels of digestible energy and crude protein in all diets were the same except that the ether extract contents were 2.76%, 7.24% and 7.24%, and the n-6/n-3 PUFA ratios were about 10∶1, 4∶1 and 2∶1, respectively. The experiment lasted for 42 d after 7 d adaption. The results showed as follows: 1) compared with the control group, dietary vegetable oils significantly increased the intramuscular fat (IMF) content in longissimus dorsi muscle of growing-finishing pigs (P<0.05), but had no effects on the average daily gain (ADG), average daily feed intake (ADFI), and feed to gain ratio (F/G) as well as the backfat thickness (P>0.05). 2) Compared with the control group, dietary vegetable oils significantly increased the contents of n-3 and total PUFAs in longissimus dorsi muscle and subcutaneous fat (P<0.05), and significantly decreased the n-6/n-3 PUFA ratio (P<0.05); compared with rapeseed oil group, the n-3 PUFA content was significantly increased in longissimus dorsi muscle and subcutaneous fat in mixed oil group (P<0.05), while the n-6/n-3 PUFA ratio was significantly decreased (P<0.05). 3) Compared with the control group, dietary vegetable oils significantly increased the mRNA relative expression levels of fatty acid translocase/CD36 (FAT/CD36) and fatty acid transport protein 1 (FATP1) in longissimus dorsi muscle and subcutaneous adipose tissue (P<0.05), and the mRNA relative expression levels of FAT/CD36 and fatty acid transport protein 4 (FATP4) in longissimus dorsi muscle in mixed oil group was significantly higher than that in rapeseed oil group (P<0.05). 4) Compared with the control group, dietary vegetable oils significantly increased the mRNA relative expression levels of carbohydrate response element binding protein (ChREBP), glucose transporter 4 (Glut4), and lipogenic genes such as fatty acid synthase (FAS), acetyl-CoA carboxylase (ACC), fatty acid elongase 5 (Elovl5) and fatty acid elongase 6 (Elovl6) in longissimus dorsi muscle, and significantly decreased the mRNA relative expression levels of peroxisome proliferator-activated receptor γ (PPARγ), retinoid X receptor α (RXRα) and lipogenic genes in subcutaneous adipose tissue (P<0.05). It is concluded that reducing dietary n-3/n-6 PUFA ratio with vegetable oil supplementation stimulates the absorption and utilization of dietary long-chain fatty acids for fat synthesis in muscle and subcutaneous adipose tissue by increasing the expression of FAT/CD36 and FATP1; inhibits de novo lipogenesis by decreasing the expression of PPARγ and lipogenic genes in subcutaneous adipose tissue, and stimulates the lipogenesis by increasing the expression of ChREBP and lipogenic genes in longissimus dorsi muscle, increasing IMF content. Furthermore, the n-3 PUFA content and n-6/n-3 PUFA ratio in the tissues can be more effectively improved by the dietary n-6/n-3 PUFA ratio of 2∶1.

This experiment aimed to investigate the effects of medium-chain fatty acids (MCFA) on growth performance, diarrhea, nutrient apparent digestibility and serum indexes of weaned piglets. Three hundred 29-day-old weaned piglets (Duroc×Landrace×large cross) with similar body weight [(6.83±0.44) kg] were randomly divided into 4 groups with 3 replicates per group and 25 pigs per replicate. The control group was fed a basal diet, and the experimental groups were fed the basal diets supplemented with 1, 2 or 4 g/kg MCFA, respectively. The experiment lasted for 35 days including a 5-day transition period. The results showed as follows: compared with the control group, dietary adding MCFA with different doses decreased the fecal score and diarrhea rate of piglets (P<0.05). Compared with control group, the apparent digestibility of ether extract of piglets fed 4 g/kg MCFA was higher (P<0.05). Piglets fed 4 g/kg MCFA had lower serum malondialdehyde content (P<0.05) and trended higher serum superoxide dismutase activtiy (0.05<P<0.10) compared with control group. Compared with control group, dietary adding MCFA with different doses increased serum immunoglobulin A content (P<0.05). Compared with control group, adding 1 and 2 g/kg MCFA trended to increase serum immunoglobulin M content (0.05<P<0.10). In conclusion, MCFA can enhance antioxidant capacity and immune ability, relive diarrhea and weaning stress in weaned piglets. However, this experiment find that it can not promote weight gain and improve feed utilization rate.

This experiment was conducted to investigate the effects of feeding diets with different levels of corn stored for 4 years instead of normal corn on growth performance, slaughter performance, meat quality and intestinal microbiota of broiler chickens. A total of 500 healthy Ross 308 commercial male broiler chickens of one-day-old with similar body weight were randomly divided into 5 groups with 10 replicates per group and 10 broilers per replicate. Broilers in the control group (group A) were fed a normal corn-soybean meal type diet, and those in groups B, C, D and E were fed diets containing 15%, 30%, 45% and 60% corn stored for 4 years, respectively. The experiment lasted for 35 days. The results showed as follows: 1) from 1 to 14 days of age, there were no significant differences in growth performance indices of broiler chickens among all groups (P>0.05); from 15 to 24 days of age, compared with the normal corn (control group), 45% or more corn stored for 4 years (groups D and E) significantly decreased the body weight at 24 days of age, average daily gain (ADG) and average daily feed intake (ADFI) of broiler chickens (P<0.05), and significantly increased the ratio of feed to gain (F/G) (P<0.05); from 25 to 35 days of age, compared with the normal corn, 45% or more corn stored for 4 years significantly decreased the body weight at 35 days of age (P<0.05), but had no significant effects on ADG, ADFI and F/G of broiler chickens (P>0.05); from 1 to 35 days of age, compared with the normal corn, 45% or more corn stored for 4 years significantly decreased ADG and ADFI of broiler chickens (P<0.05), and tended to increase F/G, but the difference was not significant (P>0.05). 2) Compared with the control group, except that the thigh muscle rate in group D was significantly increased (P<0.05), there were no significant differences in slaughter performance indices and immune organ indices in the other groups (P<0.05). 3) Compared with the control group, the malondialdehyde (MDA) content in breast muscle of broiler chickens in group E was significantly increased (P<0.05). 4) Compared with the normal corn, 30% or more corn stored for 4 years significantly increased the thiobarbiturate (TBA) value in breast muscle of broiler chickens (P<0.05), 60% corn stored for 4 years significantly decreased the pH in breast muscle (P<0.05), and the shear force of breast muscle in group E was significantly higher than that in the other groups (P<0.05). 5) Compared with the control group, the ACE index of intestinal microbiota of broiler chickens s in groups C and D was significantly decreased (P<0.05). At the phylum level, different levels of corn stored for 4 years had a negative correlation with the intestinal Firmicutes relative abundance of broiler chickens (R²=0.839 8), and had a positive correlation with the intestinal Proteobacteria relative abundance of broiler chickens (R²=0.890 5); at the genus level, there was a strong negative correlation between different levels of corn stored for 4 years and the intestinal Lactobacillus relative abundance of broiler chickens (R²=0.937 5). In conclusion, under the conditions of this experiment, broiler chickens fed diets containing more than 30% corn stored for 4 years with high fatty acid values can decrease the growth performance, antioxidant capacity and meat quality of broiler chickens, and disorder the intestinal microbiota.

The objective of this study was to evaluate the metabolizable energy and amino acids ileal digestibility of fresh fermented soybean meal in rapidly growing yellow-feathered broilers. Trial 1 was to evaluate the apparent matabolizable energy (AME) and nitrogen corrected apparent matabolizable energy (AME_n) of fresh fermented soybean meal. Forty-eight 30-day-old male rapidly growing yellow-feathered broilers were randomly allocated into 2 groups with 6 replicates per group and 4 broilers per replicate. Broilers in 2 groups were fed basal diet and experimental diet, respectively. The pre-experimental period lasted for 3 days, and the total collection period lasted for 4 days. Trial 2 was to evaluate the amino acid ileal digestibility of fresh fermented soybean meal. Seventy-two 30-day-old male rapidly growing yellow-feathered broilers were randomly allocated into 2 groups with 6 replicates per group and 6 broilers per replicate. Broilers in 2 groups were fed nitrogen-free diet and experimental diet, respectively. The experimental period lasted for 3 days. The results of trial 1 showed that on as-fed basis, the AME and AME_n of fresh fermented soybean meal were significantly lower than those of regular soybean meal (P<0.05); on dry matter basis, the AME and AME_n of fresh fermented soybean meal were significantly higher than those of regular soybean meal (P<0.05). The results of trial 2 showed that the top 4 apparent ileal digestibility (AID) of essential amino acids were methionine (82.55%), arginine (81.66%), tyrosine (80.64%) and tryptophan (80.50%), and the top 4 standardized ileal digestibility (SID) of essential amino acids were tryptophan (97.89%), methionine (91.26%), arginine (88.20%) and isoleucine (87.52%). The AID of non-essential amino acids were glutamate (80.75%), aspartate (74.17%) and proline (72.95%), and the SID of non-essential amino acids were proline (86.56%), glutamate (84.79%) and serine (83.17%). On as-fed basis, the amino acids contents in fresh fermented soybean meal were lower than those in regular soybean meal, due to the high moisture content in fresh fermented soybean meal. On dry matter basis, the amino acids contents (except tryptophan) in fresh fermented soybean meal were lower than those in regular soybean meal. Among essential amino acids, the SID of methionine, threonine and tryptophan of fresh fermented soybean meal were higher than those of regular soybean meal. In conclusion, the AME and AME_n of fresh fermented soybean meal on dry matter basis were 14.38 and 13.20 MJ/kg, which were 25.3% and 27.3% higher than regular soybean meal, it shows that the soybean meal after fermentation can improve the metabolic energy. The SID of methionine, threonine and tryptophan are improved after fermentation.

The purpose of this experiment was to explore the effects of compound probiotics with three different ratios of Lactobacillus casei, Lactobacillus acidophilus and Bifidobacterium lactis on the intestinal immunity, antioxidation and apoptosis of broilers. Four hundred 1-day-old male jute broilers were randomly divided into 4 groups with 5 replicates in each group and 20 replicates in each group. Lactobacillus casei, Lactobacillus acidophilus and Bifidobacterium lactis were formulated into composite bacterial preparations in proportions of 2∶1∶1, 1∶2∶1 and 1∶1∶2, and supplemented to drinking water at a ratio of 1% for the probiotics groupⅠ, group Ⅱ and group Ⅲ, and the normal drinking water group served as the control group. The feeding cycle was divided into 2 stages: 1 to 21 days of age and 22 to 42 days of age. The results showed as follows: during the entire growth period, compared with the control group, the average daily gain (ADG) of broilers in all probiotic groups was significantly increased (P<0.05). At 21 days of age, compared with the control group, the contents of immunoglobulin A (IgA), immunoglobulin G (IgG), interleukin-2 (IL-2) and interleukin-10 (IL-10), and total antioxidant capacity (T-AOC) and the relative expression levels of mucin 2 (MUC2), occludin, claudin-1 and B cell lymphoma-2 (Bcl-2) mRNA in the jejunum were significantly increased in the probiotic groups (P<0.05), while the relative expression levels of B cell lymphoma-2 associated X protein (Bax) and cysteine aspastic acid-specific protease 3 (Caspase-3) mRNA were significantly reduced (P<0.05). At 42 days of age, compared with the control group, the IL-10 content, superoxide dismutase (SOD) activity and T-AOC and the relative expression levels of heme oxygenase-1 (HO-1), claudin-1 and Bcl-2 mRNA in jejunum were significantly increased in the probiotic groups (P<0.05), while the relative expression levels of Caspase-3 mRNA was significantly reduced (P<0.05). In the probiotic groups, the probiotic group Ⅰ had the best effect on promoting IgA and IgG contents in intestinal mucosa; the probiotic group Ⅰ and group Ⅲ had the best effect on increasing the contents of IL-2 and IL-10 intestinal mucosa; the probiotic group Ⅲ had the best effect on promoting the intestinal barrier gene expression, increasing the antioxidant activity, up-regulating Bcl-2 and down-regulating the expression of Bax and Caspase-3 mRNA was the best. In summary, compound probiotics with different ratios of Lactobacillus casei, Lactobacillus acidophilus and Bifidobacterium lactis all can improve the growth performance of broilers, enhance the intestinal antioxidant function and immune function, alleviate intestinal apoptosis, and the mixing ratio of 1∶1∶2 has the best effect on broilers.

Probiotics can regulate gut bacteria to benefit the antioxidant capacity of animals, but little is known about the gut fungi. Thus, this study was to investigate the effects of Lactiplantibacillus plantarum P8 on the ileal morphology, antioxidant capacity and cecal fungi structure of oxidative stressed broilers. A total of 300 one-day-old broilers were allocated to three groups with 10 replicates per group and 10 broilers per replicate: control group (Con group), control diet+DEX injection group (DEX group) and control diet containing 1×10⁸ CFU/g Lactiplantibacillus plantarum P8+DEX injection group (DEX_P8 group). On day 16, broilers in the DEX and DEX_P8 groups were injected intraperitoneally with DEX. On day 21, broilers were sacrificed for the determination of ileal morphology, antioxidant indexes and fungal composition of cecal contents.Results showed as follows: 1) compared with Con group, DEX treatment had no significant effects on ileum morphology (P>0.05), but significantly decreased the contents of nuclear factor E2-related factor 2 (Nrf2), glutathione (GSH), heme oxygenase-1 (HO-1) activity and total antioxidant capacity (T-AOC) in plasma and ileum mucosa of broilers (P<0.05). Dietary Lactobacillus plantarum P8 powder had no significant effects on ileum morphology of broilers treated with DEX (P>0.05), but significantly increased the contents of Nrf2 and GSH, HO-1 activity and T-AOC in plasma and ileum mucosa of broilers treated with DEX (P<0.05). 2) ITS sequencing results showed that DEX and DEX_P8 significantly changed the fungal composition of cecal contents. Particularly, the relative abundance of Pleosporales_unclassified, Coprinellus, Hypocrea, Phomopsis, Didymella, Pleosporales_unclassified, Coprinellus_hiascenen, Trichoderma_arundimaceum, Phomopsis_unclassified, Didymella_unclassified was significantly decreased in the DEX group compared with the Con group (P<0.05), while the relative abundance of Malassezia, Malassezia_restricta was significantly increased (P<0.05). The relative abundance of Trichocomaceae, Diaporthaceae, Didymellaceae, Itersonilia, Didymella, Phomopsis, Itersonilia_perplexans, Didymella_unclassified, Phomopsis_unclassified was significantly elevated in the DEX_P8 group compared with the DEX group (P<0.05), while the relative abundance of Zygomycota, Saccharomycetaceae, Mortierellaceae, Zygosaccharomyces, Mortierella, Zygosaccharomyces_unclassified, Mortierella_elongata was significantly decreased (P<0.05). 3) Pearson’s correlation analysis indicated that the ileal GSH content was negatively correlated with the relative abundance of Saccharomyces (P<0.05). Plasmal Nrf2 content was positively correlated with the relative abundance of Itersonilia and Agaricomycetes_unclassified (P<0.05). Ileal HO-1 activity was positively correlated with the relative abundance of Thermoasus (P<0.01). Based on the above indexes, Lactobacillus plantarum P8 can effectively relieve oxidative stress and regulate the fungal structure of cecum contents in broilers under the conditions of this experiment. Correlation analysis further indicate that Lactobacillus plantarum P8 may improve the antioxidant function of broilers with oxidative stress by regulating the fungal structure of cecum.

This experiment was conducted to investigate the effects of different dietary protein levels and different additional doses of acid protease on growth performance and nutrient apparent digestibility of broilers, and to provide reference for rational use of acid protease in the diet of broilers. A 4×2 factorial design was used in this experiment. Two factors were additional dose of acid protease and dietary protein level. The four additional doses of acid protease were 0, 125, 250 and 500 g/t, respectively. The two protein level were normal protein level (basal diet) and low protein level (low protein diet with 1% lower protein level on the basis of basal diet), respectively. A total of 1 440 healthy 7-day-old white feathered broilers were randomly divided into 8 groups with 6 replicates per group and 30 broilers per replicate. Broilers in the four groups were fed the basal diet (group Ⅰ), the basal diet+125 g/t acid protease (group Ⅱ), the basal diet+250 g/t acid protease (group Ⅲ), the basal diet+500 g/t acid protease (group Ⅳ), the low protein diet (group Ⅴ), the low protein diet+125 g/t acid protease (group Ⅵ), the low protein diet+250 g/t acid protease (group Ⅶ) and the low protein diet+500 g/t acid protease (group Ⅷ), respectively. the group Ⅰ which fed the basal diet and the group Ⅴ which fed low protein diet were the control group. The experiment lasted for 42 days. The results showed as follows: 1) under the condition of basal diet, compared with the control group (group Ⅰ), the average daily gain in the early stage of group Ⅱ was significantly increased (P<0.05), the average daily feed intake and average daily gain in the later stage of groups Ⅲ and Ⅳ were significantly increased (P<0.05), and the average daily gain in the whole stage of groups Ⅱ and Ⅳ was significantly increased (P<0.05); under the condition of low protein diet, compared with the control group (group Ⅴ), the average daily gain in the early stage of group Ⅶ was significantly increased (P<0.05), and the average daily gain in the whole stage of groups Ⅶ and Ⅷ was significantly increased (P<0.05). 2) Under the condition of basal diet, compared with the control group (group Ⅰ), the apparent digestibility of dry matter of broilers of groups Ⅱ, Ⅲ and Ⅳ was significantly increased (P<0.05); the apparent digestibility of crude protein, aspartic acid, threonine, serine, glutamic acid, glycine, alanine, cystine, valine, methionine, isoleucine, leucine, tyrosine, phenylalanine, lysine, histidine, arginine and proline of broilers of groups Ⅲ and Ⅳ was significantly increased (P<0.05); under the condition of low protein diet, compared with the control group (group Ⅴ), the apparent digestibility of dry matter, cysteine, valine and tyrosine of broilers of groups Ⅵ, Ⅶ and Ⅷ was significantly increased (P<0.05); the apparent digestibility of crude protein, serine, glycine and alanine of broilers of groups Ⅶ and Ⅷ was significantly increased (P<0.05); the apparent digestibility of aspartic acid, threonine, glutamic acid, methionine, isoleucine, leucine, phenylalanine, lysine, histidine, arginine and proline of broilers of group Ⅷ was significantly increased (P<0.05). 3) Under the condition of basal diet, the profit per chicken of groups Ⅱ, Ⅲ and Ⅳ was 0.64, 0.44 and 0.62 CNY higher than that of group Ⅰ, respectively; under the condition of low protein diet, the profit per chicken of groups Ⅵ, Ⅶ and Ⅷ was 0.32, 0.63 and 0.57 CNY higher than that of group Ⅴ, respectively. In conclusion, adding acid protease in diets with different protein levels can improve the growth performance and nutrient apparent digestibility, and reduce the mortality rate of broilers. In the basal diet, 125 and 500 g/t acid protease are recommended to be added to the diets of broilers in the early and later stages of the experiment, respectively. In the low protein diet, 250 and 500 g/t acid protease are recommended to be added to the diets of broilers in the early and later stages of the experiment, respectively.

This experiment was conducted to study the effects of dietary Glycyrrhiza uralensis extract (GUE), lactic acid bacteria (LAB) and their combined supplementation on growth performance, slaughter performance, meat quality, nutrient apparent metabolic rates and serum biochemical indexes of broilers. A total of 420 one-day-old healthy male Liangfeng broilers were randomly divided into four groups with seven replicates per group and 15 broilers per replicate. They were fed basal diet (control group), basal diet+0.1% GUE (GUE group), basal diet +4.5×10⁷ CFU/g Lactobacillus acidophilus (LAB group), and basal diet+0.1% GUE+4.5×10⁷ CFU/g Lactobacillus acidophilus (GUE+LAB group), respectively. The experiment lasted for 84 d. The results showed as follows: 1) compared with the control group, the body weight of broilers in the GUE group and LAB group was significantly increased at 56 and 84 days of age (P<0.05), and the average daily gain (ADG) was significantly increased and feed/gain ratio (F/G) was significantly decreased at 57 to 84 days of age (P<0.05); the average daily feed intake (ADFI) was significantly increased at 29 to 56 days of age and 57 to 84 days of age in the GUE group and GUE+LAB group (P<0.05). The body weight at 56 and 84 days of age, the ADG and ADFI at 57 to 84 days of age, and ADFI at 1 to 84 days of age in the GUE+LAB group were significantly higher than those in the GUE group and Lac group (P<0.05). 2) Compared with the control group, the eviscerated percentage of broilers was significantly increased (P<0.05), and the abdominal fat percentage was significantly decreased in the GUE group, LAB group and GUE+LAB group (P<0.05). The abdominal fat percentage of broilers in the GUE+LAB group was significantly lower than that in the GUE group and LAB group (P<0.05). 3) The redness (a^*) value of breast muscle in the GUE group, LAB group and GUE+LAB group was significantly higher than that in the control group (P<0.05), and it in the GUE group and LAB group was significantly higher than it in the GUE+LAB group (P<0.05), but there were no significant differences in other meat quality traits among groups (P>0.05). 4) The apparent metabolic rates of crude protein (CP), ether extract (EE), and crude fibre (CF) in the GUE group, LAB group and GUE+LAB group were significantly higher than those in the control group (P<0.05), and they in the GUE+LAB group were significantly higher than those in the GUE group and LAB group (P<0.05). 5) The activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and the contents of high density lipoprotein cholesterol (HDL-C) and urea nitrogen (UN) in serum of broilers at 28 and 84 days of age were not significantly different among groups (P>0.05), while the serum total cholesterol (TC) content of broilers at 28 days of age and serum TC and LDL-C contents of broilers at 84 days of age in the GUE group and LAB group were significantly decreased compared with the control group (P<0.05). The serum contents of TC and LDL-C of broilers at 28 and 84 days of age in the GUE+LAB group were significantly lower than those in the GUE group and LAB group (P<0.05). It is concluded that GUE or LAB supplemented in diets can increase the growth performance during the growing period and finishing period and improve carcass quality and nutrient apparent metabolic rates of Liangfeng broilers without adverse effects on meat quality and liver function. Compared with the supplementation of GUE and LAB alone, combined supplementation of GUE and LAB can synergistically improve the growth performance, carcass quality, and nutrient apparent metabolic rates of broilers during the growing period and finishing period.

The aim of this study was to investigate the effects of classical music on slaughter performance and intestinal development of broilers chickens with different stocking densities. The experiment was conducted in a 2×3 factorial design (with/without music stimulation×3 stocking densities). Classical music was played in the group with music stimulation, and the three stocking density levels were 15.5, 17.9 and 20.3 birds/m², respectively. A total of 540 Cobb broilers of 1-day-old were randomly divided into 6 groups with 6 replicates per group. The experiment lasted for 42 days. The results showed as follows: 1) with the increase of stocking density, the live weight before slaughter, dressing percentage and pectoral muscle percentage of broilers were significantly decreased (P<0.05), and playing classical music significantly increased the live weight of broilers before slaughter (P<0.05). 2) Exposure to classical music had a tendency to increase the relative length of jejunum (P=0.088) and ileum (P=0.057) of broilers. 3) With the increase of stocking density, the villus height and villus height to crypt depth ratio (V/C) in duodenum, jejunum and ileum of broilers were significantly decreased (P<0.05), and the crypt depth in jejunum and ileum were significantly increased (P<0.05). Playing classical music significantly increased the villus height in jejunum of broilers (P<0.05), and had a tendency to decrease the V/C in jejunum (P=0.058) and ileum (P=0.080). Playing classical music significantly increased the V/C in ileum broilers with high stocking density (20.3 birds/m²) (P<0.05). 4) Increasing stocking density significantly decreased the relative abundances of uncultured_bacterium_f_Ruminococcaceae and Fecalibacterium in cecum of broilers (P<0.05). Playing classical music had no significant effects on cecal microflora of broilers (P>0.05). In conclusion, under the cage condition of this experiment, the stocking density of 20.3 birds/m² leads to the decrease of live weight before slaughter, slaughter percentage and pectoral muscle percentage of Cobb broilers, results in the imbalance of intestinal morphology and microflora, and the recommended stocking density is 17.9 birds/m². However, classical music stimulation can improve the live weight before slaughter and intestinal development of broilers to a certain extent. It is suggested that the stocking density of Cobb broilers can be increased to 20.3 birds/m² under the background of classical music stimulation.

This experiment was conducted to study the variation characteristics of performance, egg quality and oxidative damage in plasma, liver and oviduct of laying hens from peak to late laying period with time. A total of 135 healthy Hy-Line brown laying hens at 34 weeks of age with similar body condition were selected and 9 replicates were set with 15 hens per replicate. The experiment lasted for 48 weeks. Samples were collected at 34, 46, 58, 70 and 82 weeks of age to determine egg quality, plasma markers of oxidative damage and antioxidant enzyme activity; and markers of oxidative damage and activities of antioxidant enzymes in liver, oviduct enlargement and uterine oviduct of laying hens at 34, 58 and 82 weeks of age were also determined. The results showed as follows: 1) compared with 34, 40 and 46 weeks of age, the laying rate at 76 weeks of age was significantly decreased (P<0.05); compared with 34 and 40 weeks of age, the average egg weight at 76 weeks of age was significantly increased (P<0.05); and compared with 64 weeks of age, the broken egg rate at 82 weeks of age was significantly increased (P<0.05). 2) The eggshell strength and yolk color at 82 weeks of age were significantly lower than those at 34, 46 and 58 weeks of age (P<0.05), the egg white height and Haugh unit at 70 and 82 weeks of age were significantly lower than those at 34 and 46 weeks of age (P<0.05), and the eggshell index at 70 and 82 weeks of age was significantly higher than those at 34 and 46 weeks of age (P<0.05). 3) The contents of malondialdehyde (MDA), 8-hydroxy-deoxyguanosine (8-OHdG) and nitrotyrosine (NT) in plasma at 82 weeks of age were significantly higher than those at 34 weeks of age (P<0.05), the superoxide dismutase (SOD) activity in plasma at 58 weeks of age was significantly higher than that at 34 and 46 weeks of age (P<0.05), and the glutathione peroxidase dismutase (GSH-Px) activity and total antioxidant capacity (T-AOC) in plasma at 46 and 58 weeks of age were significantly higher than those at 34, 70 and 82 weeks of age (P<0.05); the contents of MDA, 8-OHdG and NT and T-AOC as well as the activities of SOD and GSH-Px in liver at 82 weeks of age were significantly higher than those at 34 and 58 weeks of age (P<0.05); the contents of MDA, 8-OHdG and NT in oviduct enlargement at 82 weeks of age were significantly higher than those at 34 weeks of age (P<0.05), the T-AOC and GSH-Px activity in oviduct enlargement at 82 weeks of age were significantly lower than those at 34 weeks of age (P<0.05), and the SOD activity in oviduct enlargement at 58 weeks of age was significantly higher than that at 34 and 82 weeks of age (P<0.05); the contents of MDA and 8-OHdG in uterine oviduct at 82 weeks of age were significantly higher than those at 34 weeks of age (P<0.05), the activities of SOD and GSH-Px in uterine oviduct at 58 weeks of age were significantly higher than those at 34 and 82 weeks of age (P<0.05), and the T-AOC in uterine oviduct at 58 and 82 weeks of age was significantly lower than that at 34 weeks of age (P<0.05). In conclusion, the physiological and metabolic activities of laying hens change with the increase of weeks of age from peak to late laying period, leading to the decrease of performance, egg quality, and the degradation of antioxidant capacity in oviduct enlargement and uterine oviduct of laying hens.

This study was conducted to conducted the effects of dietary different supplemental levels of sacha inchi oil (SO) on performance, egg quality, and enrichments of ω-3 polyunsaturated fatty acids (PUFA) and vitamin E in egg yolk of laying hens. A total of 450 forty-week-age Hy-line brown laying hens were randomly assigned to 5 groups with 6 replicates in each group and 15 laying hens in each replicate. The different groups were assigned to either diet with corn oil at 0.67% (control group) or flaxseed oil at 2.0% (FO group), or SO at 2.0% (SO_2.0 group), 2.5% (SO_2.5 group) and 3.0% (SO_3.0 group), respectively. The experiment lasted for 12 weeks. The results showed as follows: 1) compared with the control group, dietary different supplemental levels of SO had no significant effects on laying rate, average daily feed intake, feed to egg ratio and egg quality (P>0.05), while the average egg weight of the SO_3.0 group was significantly increased (P<0.05). 2) Compared with the control group, dietary different supplemental levels of SO significantly improved the ω-3 PUFA content in egg yolk (P<0.05), and significantly reduced the ratio of ω-6/ω-3 PUFA (P<0.05). The deposition efficiency of ω-3 PUFA in egg decreased gradually with the increase of SO supplemental level, and the SO_2.5 group was similar to FO group. 3) Compared with the control group, dietary different supplemental levels of SO had no significant effects on the total content of vitamin E in egg yolk (P>0.05). It can be concluded that the ω-3 PUFA deposition in egg yolk is greatly increased and the ω-6/ω-3 PUFA ratio is decreased when the laying hens’ diet supplemented with SO, which has no adverse effects on the performance and egg quality. SO can be used to produce ω-3 PUFA fortified egg.

This study was conducted to investigate the effects of the protein level and amino acid balance quantity of corn-soybean meal-cottonseed meal type diet on performance, egg quality, nutrient apparent metabolic rates and nitrogen emission of laying hens, in order to explore the feasibility of corn-soybean meal-cottonseed meal type low-protein diet in laying hen production, and to determine the appropriate protein level and reasonable amino acids balance model. A total of 504 healthy 400-day-old Hy-line Brown laying hens were randomly divided into 7 groups with 6 replicates per group and 12 hens per replicate. The type of diets for all groups was corn-soybean meal-cottonseed meal type. The dietary protein level of group 1 (control group) was 15.5 %. On the basis of the dietary protein level of control group, the dietary protein levels of groups 2, 3 and 4 were decreased by 1.5% and methionine (Met)+lysine (Lys), Met+Lys+threonine (Thr), Met+Lys+Thr+tryptophan (Trp) were balanced, respectively; the dietary protein levels of groups 5, 6 and 7 were decreased by 3.0% and Met+Lys, Met+Lys+Thr, Met+Lys+Thr+Trp were balanced, respectively. The experiment lasted for 91 days, including 7 days of pre-test and 84 days for formal test. The results showed as follows: 1) dietary protein level significantly affected laying rate and feed to egg ratio (P<0.05). Amino acid balance quantity significantly affected laying rate (P<0.05). Dietary protein level and amino acid balance quantity had significant interactions on laying rate and feed to egg ratio (P<0.05). Compared with the control group, there were no significant effects in the performance indicators of groups 2, 3 and 4, but the laying rate of groups 5, 6 and 7 decreased significantly (P<0.05), and the feed to egg ratio increased significantly (P<0.05). 2) Dietary protein level and amino acid balance quantity had no significant effects on egg quality indexes (P>0.05). Moreover, there were no significant interactions between dietary protein level and amino acid balance quantity on egg quality indexes (P>0.05). 3) Dietary protein level significantly affected the apparent metabolic rate of crude protein (P<0.05). Amino acid balance quantity had no significant effects on the apparent metabolic rates of crude protein, energy and ash (P>0.05). Dietary protein level and amino acid balance quantity had a significant interaction on apparent metabolic rate of crude protein (P<0.05). Compared with the control group, the apparent metabolic rate of crude protein of groups 2, 3 and 4 was significantly increased (P<0.05). 4) Dietary protein level and amino acid balance quantity significantly affected the contents of indole, skatole and ammonia in feces of laying hens (P<0.05). Dietary protein level and amino acid balance quantity had significant interactions on the contents of indole, skatole and ammonia in feces of laying hens (P<0.05). Compared with the control group, the content of indole in feces of groups 3, 4, 5, 6 and 7 was significantly reduced (P<0.05), and the contents of skatole and ammonia in feces of groups 2, 3, 4, 5, 6 and 7 were significantly reduced (P<0.05). 5) The profit of groups 2, 3 and 4 was higher than that of control group, and the economic benefit of group 2 was the highest. In summary, under this experimental condition, the corn-soybean meal-cottonseed meal type low-protein diet is feasible to apply in the production of laying hens. The protein level of the corn-soybean meal-cottonseed meal type diet can be reduced from 15.5% to 14.0% along with the balance of Met and Lys has no negative effect on the performance and egg quality of laying hens, moreover, it can improve the apparent metabolic rate of crude protein and reduce the nitrogen emission of laying hens, which has the highest economic benefit, at this time, the dietary amino acid balance pattern is Lys∶Met∶Thr∶Trp=100∶45∶54∶15. However, when the protein level of the corn-soybean meal-cottonseed meal type diet is reduced from 15.5% to 12.5%, even the balance of Met, Lys, Thr and Trp, it still has a negative impact on performance.

This experiment was conducted to investigate the effects of different forms and levels of dietary vitamin D on growth performance and plasma biochemical indices of Peking ducks aged 14 to 35 days to determine the requirements of 25-hydroxyvitamin D₃ (25-OH-D₃) and vitamin D₃ and their relative bioefficacy. A total of 728 healthy male Peking ducks at 14 days of age with similar body weight were randomly divided into 13 groups with 8 replicates per group and 7 ducks per replicate. One basal diet group (without vitamin D), six 25-OH-D₃ supplemental groups and six vitamin D₃ supplemental groups were set up, and the supplemental levels were 100, 200, 400, 800, 1 200 and 2 000 IU/kg. The trial lasted for 3 weeks. Results showed as follows: 1) compared with the basal diet group, dietary vitamin D₃ supplementation had no significant effects on the growth performance of Pekin ducks aged 14 to 35 days (P>0.05), but dietary 25-OH-D₃ supplementation significantly increased the average body weight and average daily gain (P<0.05). However, there was no significant difference in growth performance between the two supplemental forms of vitamin D (P>0.05). 2) Compared with the basal diet group, dietary supplementation of vitamin D₃ or 25-OH-D₃ significantly decreased the plasma alkaline phosphatase activity (P<0.05), and significantly increased the plasma calcium content (P<0.05) of Pekin ducks at 35 days of age. However, there was no significant difference between the two groups (P>0.05), and there was a significant interaction between the two forms and dietary vitamin D levels (P<0.05). 3) With the increase of vitamin D₃ or 25-OH-D₃ supplemental levels, the plasma 25-OH-D₃ content showed a significant linear increase and quadratic change (P<0.01), and there was a significant interaction between the two forms and dietary vitamin D levels (P<0.05). Moreover, the plasma 25-OH-D₃ content in the 25-OH-D₃ supplemental group was significantly higher than that in the vitamin D₃ supplemental group (P<0.05). 4) Using plasma alkaline phosphatase activity and calcium content as evaluation indexes, the quadratic curvilinear model was used to estimate that the vitamin D₃ requirement of Pekin ducks aged 14 to 35 days was 440.7 and 100.0 IU/kg, respectively, and the 25-OH-D₃ requirement was 100.0 IU/kg. 5) Using plasma alkaline phosphatase and 25-OH-D₃ content as evaluation indexes, the relative bioefficacy of 25-OH-D₃ in Pekin ducks aged 14 to 35 days was estimated to be 2.16 and 2.37 times that of vitamin D₃ by the index model. In conclusion, dietary supplementation of vitamin D₃ or 25-OH-D₃ can increase plasma calcium and 25-OH-D₃ contents, as well as reduce alkaline phosphatase activity; however, dietary supplementation of 25-OH-D₃ has a higher deposition efficiency of 25-OH-D₃ in plasma and can improve the growth performance of meat ducks.

This experiment was conducted to study the effects of Bacillus coagulans and Clostridium butyricum on growth performance, slaughter performance, serum biochemical indexes and intestinal health of meat ducks. A total of 180 healthy 7-day-old Cherry Valley ducks were selected and divided into 6 groups according to their weight, with 5 replicates in each group and 6 ducks in each replicate. The control group was fed a basal diet, the BC group was fed basal diet supplemented with Bacillus coagulans, the CB group was fed the basal diet supplemented with Clostridium butyricum, the BC+CB group (1∶1) group was fed the basal diet supplemented with Bacillus coagulans and Clostridium butyricum (mixed with 1∶1 ratio), the BC+CB group (1∶2) group was fed the basal diet supplemented with Bacillus coagulans and Clostridium butyricum (mixed with 1∶2 ratio), the BC+CB group (2∶1) group was fed the basal diet supplemented with Bacillus coagulans and Clostridium butyricum (mixed with 2∶1 ratio), and the dietary total addition of probiotics was 0.3%. The pre-experimental period lasted for 5 days, and the experimental period lasted for 42 days. The results showed as follows: 1) compared with the control group, the average daily weight gain during 12 to 35 days of age and 12 to 49 days of age of BC+CB (1∶2) group was significantly increased (P<0.05), and the feed to gain ratio during 12 to 35 days of age and 12 to 49 days of age of BC+CB (1∶2) group and BC+CB (2∶1) group was significantly decreased (P<0.05). 2) There were no significant differences in dressing percentage, semi-eviscerated rate, eviscerated rate, breast muscle rate, leg muscle rate and abdominal fat rate among all groups (P>0.05). 3) The contents of high-density lipoprotein cholesterol, total protein and albumin in serum of BC+CB (1∶2) group and BC+CB (2∶1) group were significantly higher than those of the control group (P<0.05), and the serum alanine aminotransferase activity was significantly lower than that of control group and BC group (P<0.05). There were no significant differences in serum low density lipoprotein cholesterol, triglyceride, total amino acid contents and alkaline phosphatase, glutamic-oxaloacetic transaminase activities among all groups (P>0.05). 4) The intestinal secretory immunoglobulin A content of BC+CB (2∶1) group was significantly higher than that of control group and BC group (P<0.05). There were no significant differences in contents of tumor necrosis factor-α and interleukin-1β in intestine among all groups (P>0.05). 5) Compared with the control group, the villus height and villus height to crypt depth ratio in duodenum and ileum of BC+CB (1∶1) group, BC+CB (1∶2) group and BC+CB (2∶1) group were significantly increased (P<0.05). 6) Compared with the control group, the relative abundances of Ruthenibacterium and Erysipelatoclostrichaceae-unclassified in caecum of BC+CB (2∶1) group were significantly increased (P<0.05), and the relative abundances of Halomonas, Halomonadaceae, Oceanospillales and Kocuria in caecum were significantly decreased (P<0.05). In conclusion, compared with single bacterial preparation, Bacillus coagulans and Clostridium butyricum compound bacterial preparation is more conducive to promoting the growth performance of Cherry Valley ducks, increasing the contents of total protein, albumin, high-density lipoprotein cholesterol in serum, decreasing the serum alanine aminotransferase activity, improving the small intestine morphology, improving the immunity, and maintaining the intestinal flora structure. Under the test conditions, when the proportion of Bacillus coagulans and Clostridium butyrate is 2∶1, the effect is the best.

The purpose of this experiment was to study the effects of dietary vitamin B₁ supplemental level on reproductive performance, serum reproductive hormone indices, intestinal tissue morphology and cecal flora structure of breeding geese during laying period. A total of 150 thirty-four-weeks-old Wulong breeding geese with similar body conditions were selected and randomly divided into 6 groups with 5 replicates in each group and 5 geese (1 male and 4 female) in each replicate. The vitamin B₁ supplemental levels in 5 groups were 0 (control group), 1, 2, 3, 4 and 5 mg/kg, respectively. The pre-experimental period lasted for 1 week, and the experimental period lasted for 10 weeks. The results showed as follows: 1) there was no significant difference in the qualified rate of breeding eggs, fertilization rate of breeding eggs and hatchability rate of breeding eggs among all groups (P>0.05). 2) There was no significant difference in the contents of prolactin, luteinizing hormone, estradiol and testosterone in serum among all groups (P>0.05). The serum progesterone content of 2 mg/kg vitamin B₁ group was significantly higher than that of control group and 1, 3, 4 and 5 mg/kg vitamin B₁ groups (P<0.05), and the serum follicle-stimulating hormone content of 2 and 3 mg/kg vitamin B₁ group was significantly higher than that of the control group (P<0.05). 3) The jejunum and ileum villus height/crypt depth of 2 mg/kg vitamin B₁ group was significantly higher than that of control group and 5 mg/kg vitamin B₁ group (P<0.05). 4) The cecal flora Invsimpson index of 2 mg/kg vitamin B₁ group was significantly lower than that of the control group (P<0.05). At family level, the relative abundances of Campylobacteraceac, Cellulomonadaceae and Methylobacteriaceae in cecum of 2 mg/kg vitamin B₁ group were significantly lower than those of the control group (P<0.05). At genus level, the relative abundance of Faecalibacterium in cecum of 2 mg/kg vitamin B₁ group were significantly higher than that of the control group (P<0.05). To sum up, the addition of vitamin B₁ in the diet is conducive to improving the serum reproductive hormone contents of breeding geese during laying period, promoting the development of intestinal tissue, and optimizing the cecal flora structure. Therefore, it is suggested that the supplemental level of vitamin B₁ for breeding geese during laying period is 2 mg/kg.

This study was to investigate the effects of mustard seed extract (MSE) on nitrogen metabolism, urinary nitrogen components and urinary nitrous oxide (N₂O) emissions of beef cattle. Six castrated steers (Luxi cattle×Limousin cattle) with body weight of (494.7±43.4) kg were used as experimental animals, and 0, 120 g/d MSE were supplemented to the basal diet as experimental treatments, respectively. A replicated 2×2 Latin square design was adopted and three steers were used for each treatment as replicates. Each experimental period lasted for 20 days, including 15 days for adaptation and 5 days for sampling. The results showed as follows: 1) dietary supplementation with 120 g/d MSE had no significant effects on fecal nitrogen, urinary nitrogen, total nitrogen excretions, fecal nitrogen/urinary nitrogen, nitrogen retention, nitrogen utilization rate and average daily gain of beef cattle (P>0.05). 2) Dietary supplementation with 120 g/d MSE had no significant effects on excretions of urea, allantoin, uric acid, hippuric acid and creatinine in urine (P>0.05), but significantly increased urinary thiocyanates (TC) content and TC excretion (P<0.05). 3) Dietary supplementation with 120 g/d MSE had no significant effects on steer urine N₂O-nitrogen emission and N₂O-nitrogen emission factor (P>0.05). In conclusion, dietary supplementation with 120 g/d MSE do not affect the nitrogen metabolism and urinary nitrogen components. The glucosinolates and their secondary metabolites in MSE are converted into thiocyanates in beef steer body and TC is excreted into the urine. The urinary TC do not affect the urine N₂O emission in beef steers, this could possibly be attributed to the low urinary TC content.

This experiment was conducted to investigate the differences in slaughter performance, protein metabolism, immune function and antioxidant capacity of Chinese Simmental cattle and their hybrid cattle. Three Chinese Simmental cattle, three Chinese Simmental×Chinese Holstein cattle (SH), and three Chinese Simmental×Mongolian cattle (SM) were selected in the experiment. The slaughter performance and serum biochemical indexes of cattle were determined. The results showed that: three kinds of fattening cattle had no significant differences in the initial body weight, final body weight, carcass body weight, slaughter rate and average daily gain (P>0.05). The serum creatinine (Cr), albumin (ALB) contents and aspartate aminotransferase (AST) activity of SM were significantly higher than those of Chinese Simmental cattle and SH (P<0.05). The activity of creatine phosphokinase (CPK) in serum of SM was significantly higher than that of Chinese Simmental cattle (P<0.05), but there was no significant difference compared with SH (P>0.05). There were no significant differences in serum free amino acid (FAA), urea nitrogen (UN), total protein (TP), uric acid (UA) contents and alanine aminotransferase (ALT) activity among the three kinds of fattening cattle (P>0.05). The serum immunoglobulin M (IgM) content of SM was significantly lower than that of Chinese Simmental cattle and SH (P<0.05), but there was no significant difference between Chinese Simmental cattle and SH (P>0.05). There were no significant differences in the contents of serum immunoglobulin A (IgA), immunoglobulin G (IgG), interleukin-2 (IL-2) and interleukin-4 (IL-4) among the three kinds of fattening cattle (P>0.05). The content of serum malondialdehyde (MDA)of SM was significantly higher than that of Chinese Simmental cattle and SH (P<0.05). The serum catalase (CAT), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) activities and total antioxidant capacity (T-AOC) showed no significant difference among the three kinds of fattening cattle (P>0.05). The above results indicate that, for three kinds of fattening cattle, the SM has the better protein metabolic capability, and the immunity of Chinese Simmental cattle and SH is better.

The purpose was to study the effects of feeding Wenshan cattle with Panaxnotoginseng residue on growth performance, serum biochemical indexes, muscle nutrient composition, amino acid and fatty acid contents. Thirty healthy Wenshan bulls with similar body weight [about (369.68±6.57) kg] and about 18 months of age were divided into 3 groups with 10 cows in each group. The cows were fed a basal diet as control group, the basal diet supplemented with 3% Panaxnotoginseng residue was groupⅠ, and the basal diet supplemented with 6% Panaxnotoginseng residue was group Ⅱ. The pre-feeding period was 7 days and the formal period was 90 days. The results showed as follows: 1) Panaxnotoginseng residue was rich in crude protein, starch, crude fat and other nutrients, especially starch content up to 152 g/kg, and it also contained crude polysaccharide, saponin and other active ingredients. 2) The final weight, average daily gain, body oblique length, chest circumference and abdominal circumference of group Ⅰ were significantly higher than those of control group (P<0.05), and the ratio of feed to gain was significantly lower than that of control group (P<0.05). 3) The activities of serum aspartate aminotransferase, cholinesterase, alkaline phosphatase and lactate dehydrogenase and the content of total bile acid of groups Ⅰ and Ⅱ were significantly lower than those of control group (P<0.05). 4) The contents of aspartic acid, alanine and lysine of group Ⅰ were significantly higher than those of control group (P<0.05), and the contents of glutamic acid and leucine of groups Ⅰ and Ⅱ were significantly higher than those of control group (P<0.05). 5) The contents of oleic acid and linoleic acid of groups Ⅰ and Ⅱ were significantly higher than those of control group (P<0.05), and the contents of cardamic acid, palmitic acid and stearic acid of groups Ⅰ and Ⅱ were significantly lower than those of control group (P<0.05). In conclusion, feeding Wenshan cattle with Panaxnotoginseng residue doesn’t damage to animal body. In addition, it can increase average daily gain and feed conversion rate, but also reduce feed to gain ratio, and it also can improve serum biochemical indexes of Wenshan cattle to have a certain regulation effect on body metabolic function and improvement on muscle quality. Under the conditions of this experiment, feeding Wenshan cattle with 3% Panaxnotoginseng residue has a significant effect, and the development and utilization of Panaxnotoginseng residue as feed resource has great potential.

This experiment was conducted to investigate the effects of N-carbamylglutamate(NCG) supplementation in different doses on microflora composition in rumen and rectum of Holstein bulls. Forty-five healthy Holstein bulls [initial body weight (478±13.66) kg, 12 to 13 months of age] were randomly divided into three groups, and there were 15 bulls in each group, 0 (group Ⅰ), 15 (group Ⅱ) and 25 g/(d·bull) NCG(group Ⅲ) were added in a basal diet, respectively. The pre-test period lasted for 7 days and the experimental period lasted for 90 days. Results showed as follows: with the increase of NCG supplemental dose, rumen microbial diversity was not significantly affected (P>0.05), but the relative abundance of Bacteroidetes showed linear decreasing trend (0.05<P<0.10), while the relative abundance of Firmicutes showed linear increasing trend (0.05<P<0.10). At genus level, the relative abundance of Ruminococcus 1 in group Ⅱ was significantly higher than that in group Ⅰ (P<0.05). The relative abundance of Ruminococcaceae UCG-005 showed increasing trend (P=0.05), and the relative abundance of Succinivibrio showed linear increasing with the increase of NCG supplemental dose (P<0.05), and the relative abundance of Lachnospiraceae 2 showed linear increasing trend with the increase of NCG supplemental dose (0.05<P<0.10). In the rectal microflora, the diversity of rectal microflora showed liner increasing trend with the increase of NCG supplemental dose (P>0.05). At phylum level, the supplement of NCG had no significant effect on rectal microflora (P>0.05), but the relative abundance of Patescibacteria showed quadratic curve change with the increase of NCG dose (0.05<P<0.10). At genus level, the relative abundance of Rikenellaceae RC9 gut group showed liner increasing trend with doses the increase of NCG (0.05<P<0.10), the relative abundance of Bifidobacterium and Ruminococcaceae UCG-010 in group Ⅱ was significantly higher than that in group Ⅰ (P<0.05), and there was no significant difference compared with group Ⅲ (P>0.05). In conclusion, the addition of NCG does not significantly increase the relative abundance of microorganisms in rumen and rectum except for Rumenococcus 1 at rumen genus level and Bifidobacterium and Ruminococcaceae UCG-010 at rectum genus level.

This experiment was conducted to investigate the effects of shed feeding and semi-shed feeding patterns on milk quality, rumen fermentation and serum antioxidant and immune indices of Jersey cattle in the Tibetan Plateau. Twelve healthy Jersey cattle from plateau were randomly divided into two groups, six cattle grazed and supplemented with concentrate were semi-shed feeding group, and the other six cattle fed the total mixed ration (TMR) were shed feeding group. The preliminary trial period lasted for 14 days, and the experimental period lasted for 41 days. The results showed as follows: 1) the feed intake in the shed feeding group was higher than that in the semi-shed feeding group, and the contents of lactose, milk protein and non-fat milk solids in the shed feeding group were significantly higher than those in the semi-shed feeding group (P<0.05). 2) The concentrations of acetate, propionate and ammonia nitrogen in rumen in the shed feeding group were significantly higher than those in the semi-shed feeding group (P<0.05). 3) Chao1 index, which was a rumen microflora alpha diversity index, in the semi-shed feeding group was significantly higher than that in the shed feeding group (P<0.05); the Actinobacteria relative abundance in rumen in the shed feeding group was significantly higher than that in the semi-shed feeding group (P<0.05), and the Ruminococcus relative abundance in rumen in the shed feeding group tended to be higher than that in the semi-shed feeding group (P>0.05). 4) There were no significant differences in serum total antioxidant capacity, malondialdehyde content and the activities of glutathione peroxidase and superoxide dismutase between two groups (P>0.05), but the contents of interleukin-6, immunoglobulin M and tumor necrosis factor-α in serum in the semi-shed feeding group were significantly higher than those in the shed feeding group (P<0.05). In conclusion, the shed feeding with TMR can provide balanced nutrition for Jersey cattle in Tibet plateau, increase rumen volatile fatty acids and ammonia nitrogen concentrations, increase milk yield and improve milk quality, but reduce rumen microflora richness; the shed feeding and semi-shed feeding have no different significant effects on serum antioxidant indices of Jersey cattle, and the immunity of Jersey cattle in the semi-shed feeding group is higher than that in the shed feeding group.

This study explored the anti-inflammatory mechanism of Lonicerae japonicae flos in dairy cow production through the method of network pharmacology, and verified by molecular docking technology. The main effective components and their targets of Lonicerae japonicae flos were screened using the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) database, and the inflammatory targets were collected through GeneCards, DisGeNET and PubMed databases. The intersection targets of Lonicerae japonicae flos and inflammation were imported into STRING database to obtain the protein-protein interaction (PPI) network diagram, and the “effective component-potential target-pathway” network diagram was obtained by Cytoscape 3.9.1 software and its plug-in CytoNCA to screen out the core targets in PPI network. The gene ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis was performed for the target of Lonicerae japonicae flos-inflammatory intersection using David database. Finally, PyMOL software was used for molecular docking to verify the binding activity of key effective components and core targets. The results showed as follows: 1) a total of 23 effective components of Lonicerae japonicae flos and 158 intersection targets of Lonicerae japonicae flos and inflammation were obtained. 2) PPI network mainly involved core targets such as tumor necrosis factor (TNF), interleukin-6 (IL-6), interleukin-1β (IL-1β), serine threonine protein kinase 1 (AKT1), and prostaglandin-endoperoxide synthase 2 (PTGS2). 3) A total of 168 biological processes, 16 cell compositions and 38 molecular functions were obtained by GO functional enrichment analysis (P<0.05), and KEGG pathway enrichment analysis showed 20 related signaling pathways (P<0.05), mainly involving three important signaling pathways as Janus kinase-signal transductor and transcriptional activator (JAK-STAT), Forkhead transcription factor O subfamily protein (FoxO) and mitogen-activated protein kinase (MAPK) signaling pathways. 4) Molecular docking results showed that two important effective components of Lonicerae japonicae flos, luteolin and quercetin, were stable to bind to the core target IL-1β. In conclusion, this study reveals the multi-component, multi-target and multi-pathway anti-inflammatory mechanism of Lonicerae japonicae flos in dairy cows through network pharmacology and molecular docking, and verifies the stability of the key effective components of Lonicerae Japonicae Flos, luteolin and quercetin, and the core target IL-1β, which provides a theoretical basis for the further application of honeysuckle in dairy cow production.

This experiment was conducted to investigate the effects of rare earth-chitosan chelate (RECC) on growth performance, nutrient apparent digestibility and rumen bacterial flora structure of buffalo calves. Eighteen healthy 100-day-old weaned buffalo male calves with body weight of (72.45±4.26) kg were randomly divided into 3 groups with 6 calves per group. Calves in the control group were fed a basal diet without RECC, and the others in experimental groups Ⅰ and Ⅱ were fed the basal diet supplemented with 0.03% and 0.06% RECC, respectively. The pre-trial period lasted for 7 days and the experimental period lasted for 60 days. The results showed as follows: 1) compared with the control group, the average daily feed intake of roughage in experimental group Ⅱ was significantly increased (P<0.05). 2) Compared with the control group, the dry matter apparent digestibility in experimental groups Ⅰ and Ⅱ was significantly increased (P<0.05). 3) At the phylum level, the top 4 dominant phyla in each group were Proteobacteria, Firmicutes, Bacteroidetes and Fibrobacteres, and there was no significant difference in their relative abundances among all groups (P>0.05). At the genus level, the Selenomonas relative abundance in experimental group Ⅰ was significantly lower than that in the control group and experimental group Ⅱ (P<0.05); compared with the control group, the Acinetobacter relative abundance in experimental groups Ⅰ and Ⅱ was significantly decreased (P<0.05). 4) Spearman correlation analysis showed that the crude protein apparent digestibility was significantly positively correlated with the relative abundances of Olsenella and Succinivibrionaceae_unclassified (r=1.0, P<0.05), the neutral detergent fiber apparent digestibility was extremely significantly negatively correlated with the Acinetobacter relative abundance (r=-1.0, P<0.01), and the acid detergent fiber apparent digestibility was significantly positively correlated with the relative abundances of Olsenella, Acinetobacter and Succinivibrionaceae_unclassified (r=1.0, P<0.05). In conclusion, dietary RECC supplementation can improve the growth performance and nutrient apparent digestibility and regulate the structure of rumen microflora of buffalo calves, and the effect of 0.06% supplemental level is better.

The purpose of this experiment was to study the energy digestion and metabolism and growth requirement of yak calves in later growth stage. Twenty-one healthy Datong yak calves (bulls) with similar date of birth and average body weight of (60.44±4.59) kg were randomly divided into three groups: initial slaughter group (average body weight of 73.61 kg, IS group), middle slaughter group (average body weight of 81.96 kg, MS group), final slaughter group (average body weight of 96.53 kg, FS group), there were 7 replicates in each group and 1 calf in each replicate. The pre-trial period was 15 days and the trial period was 60 days. All yak calves were fed in single pens, free feeding and drinking water. When the average weight of calves reached 73.61, 81.96 and 96.53 kg, the digestion and metabolism, gas metabolism and slaughter tests were carried out. The results showed as follows: 1) with the body weight of yak calves increased, the body weight before slaughter and empty body weight were significantly increased (P<0.05). 2) With the body weight of yak calves increased, the apparent digestibility of dry matter, calcium and phosphorus was significantly decreased (P<0.05), and the apparent digestibility of neutral detergent fiber was significantly increased (P<0.05). The apparent digestibility of inorganic matter, nitrogen and acid washing fiber of IS group was significantly higher than that of MS group and FS group (P<0.05). 3) With the body weight of yak calves increased, the gross energy, fecal energy, urinary energy and digestive energy were significantly increased (P<0.05), and the total energy metabolic rate and digestive energy metabolic rate were significantly decreased (P<0.05). The metabolic energy and total energy digestibility of IS group and MS group were significantly higher than that of FS group (P<0.05). 4) The oxygen consumption and carbon dioxide output of FS group were significantly higher than those of IS group and MS group (P<0.05). 5) The total energy of muscle and skin of FS group and MS group was significantly higher than that of IS group (P<0.05), and the total energy of hair of FS group was significantly higher than that of IS group and MS group (P<0.05). 6) The net energy for growth when average daily gain of 100.00 to 500.00 g/d was 1.19 to 5.95 MJ/d, and the model of net energy requirement for growth was: log10 energy=0.910 6+0.989 8 log10 empty body weight. In conclusion, according to the digestion and metabolism characteristics of energy of yak calves in late growth stage, the regression model of net energy requirement for growth of yak calves in late growth stage is established, and the nutrient parameters of energy requirement are obtained, which provides a reference for scientific feeding of yak calves.

The purpose of this experiment was to investigate the effects of alfalfa hay, oat hay and their mixed feeding on compound stomach morphology and digestive enzyme activities of yak calves during lactation period. Twenty-one healthy 45-day-old yak calves (males) with similar body weight were randomly divided into 3 groups: AH group (milk replacer+starter+alfalfa hay), OH group (milk replacer+starter+oat hay) and AO group (milk replacer+starter+alfalfa hay+oat hay, alfalfa hay∶oat hay=1∶1), each group contained 7 calves. The dietary roughage to concentrate ratio was 3∶7. The pre-experimental period lasted for 21 days, and the experimental period lasted for 120 days. The results showed as follows: 1) the final body weight, rumen weight, reticulum weight, omasum weight and abomasum weight of AO group were significantly higher than those of AH and OH groups (P<0.05). 2) The papillary width, muscular layer thickness, mucosal epithelium thickness, submucous layer thickness and plasma membrane layer thickness in rumen of AO group were extremely significantly higher those of AH and OH groups (P<0.01). 3) The mucosal epithelium thickness papillary width and muscular layer thickness in reticulum of AO group were significantly higher than those of AH and OH groups (P<0.05), and the submucous layer, thickness papillary length and plasma membrane layer thickness were extremely significantly higher than those of AH and OH groups (P<0.01). 4) The muscular layer thickness in omasum of AO group was significantly higher than that of AH and OH groups (P<0.05), and the mucosal epithelium thickness, submucous layer thickness, papillary width, papillary length and plasma membrane layer thickness were extremely significantly higher than those of AH and OH groups (P<0.01). 5) The mucosal epithelium thickness and mucosal muscle layer thickness in abomasum of AO group were significantly higher than those of AH and OH groups (P<0.05), and the submucous layer thickness, muscular layer, thickness and plasma membrane layer thickness were extremely significantly higher than those of AH and OH groups (P<0.01). 6) In rumen, the cellulase, amylase and xylanase activities of AO group were extremely significantly higher than those of AH and OH groups (P<0.05), and the endoglucanase activity was significantly higher than that of AH and OH groups (P<0.05); in reticulum, the lipase activity of AO group was extremely significantly higher than that of AH and OH groups (P<0.01), and the cellulase and pepsin activities were significantly higher than that of AH and OH groups (P<0.05); in omasum, the lipase activity of AO group was extremely significantly higher than that of AH and OH groups (P<0.01), and the cellulase and aminopeptidase activities were significantly higher than that of AH and OH groups (P<0.05); in abomasum, the chymosin activity of AO group was extremely significantly higher than that of AH and OH groups (P<0.01). In conclusion, on the basis of feeding milk substitute and starter of yak calves, compare with the single feeding alfalfa hay or oat hay diets, feeding the combination of alfalfa hay and oat hay is more beneficial to the development of compound stomach and secretion of digestive enzymes of yak calves during lactation period.

The purpose of this experiment was to study the effects of partial substitution of peanut vine by semi-dry ammoniated wheat straw silage on lactation performance, nutrient digestibility, serum biochemical indices and antioxidant indices of Laoshan dairy goats. Forty healthy dairy goats with body weight of (51.23±2.23) kg and milk yield of (1.41±0.26) kg/d, the same parity (2 parities) and in lactation 100 to 110 d were selected and divided into 2 groups according to source by paired design, with 4 replicates per group and 5 goats per replicate. The goats in control group (CG) were fed a basal diet, and the goats in semi-dry ammoniated wheat straw silage group (SG) were fed an experimental diet. The experimental diet was formulated by replacing peanut vine with 10% semi-dry ammoniated wheat straw silage in the basal diet (dry matter basis). The experiment period was 40 days, including 10 days of pre-test and 30 days of formal test. The results showed as follows: compared with the CG, using 10% semi-dry ammoniated wheat straw silage equivalently to replace peanut vine had no significant differences in milk yield, milk composition and serum antioxidant indices (P>0.05), but could significantly decrease the average daily feed intake (P<0.05), and extremely significantly increase the digestibility of dry matter, crude protein, neutral detergent fiber and acid detergent fiber (P<0.01). And that, the contents of total protein and globulin in serum of SG were also extremely significantly increased compared with CG (P<0.01). In summary, using 10% semi-dry ammoniated wheat straw silage equivalently to replace peanut vine can improve the nutrient digestibility of Laoshan dairy goats, and has no adverse effect on the milk yield, milk composition and antioxidant performance.

In this experiment, the effects of different doses of Artemisia ordosica polysaccharide on the in vitro rumen fermentation function of Albas white cashmere goats were investigated by measuring the rumen fermentation parameters at each time point of culture and combining the multiple-factors associative effect index (MFAEI) using the in vitro batch culture method to provide theoretical support for the development of new alternative antibiotic products for cashmere goats and the rational utilization of Artemisia ordosica resources. Using Inner Mongolian Albas white cashmere goat as rumen fluid donor animals in a completely randomized test design, 0 (C group, as control group), 0.1% (AOP1 group), 0.2% (AOP2 group), 0.3% (AOP3 group) and 0.45% (AOP4 group) of Artemisia ordosica polysaccharide were added to the fermentation substrate and to measure the rumen fermentation parameters after incubated for 3, 6, 9, 12 and 24 h, respectively. The results showed that the ammoniacal nitrogen (NH₃-N), bacterial protein (BCP) concentrations and gas production increased in a significant linear and quadratic curve with the addition dose of Artemisia ordosica polysaccharide increase (P<0.05), and the pH and protozoa number decreased in a significant linear and quadratic curve (P<0.05). Isobutyric acid, valeric acid and isovaleric acid concentrations showed a significant linear and quadratic curve increase with the addition dose of Artemisia ordosica polysaccharide increase (P<0.05), propionic acid concentration showed a significant linear increase (P<0.05), acetic acid concentration and acetic acid/propionic acid value showed a significant linear and quadratic curve decrease (P<0.05), while total volatile fatty acids (TVFA) concentration did not differ significantly among groups (P>0.05). With the addition dose of Artemisia ordosica polysaccharide increase, the single-factor associative effect index (SFAEI) of BCP, isobutyric acid, valeric acid and isovaleric acid concentrations showed a significant linear and quadratic curve increase (P<0.05), the SFAEI of NH₃-N and propionic acid concentrations showed a significant linear increase (P<0.05), the SFAEI of protozoa number and acetic acid concentration showed a significant linear and quadratic curve decrease (P<0.05), and the MFAEI showed a significant linear and quadratic curve increase (P<0.05). The following order of MFAEI from high to low was AOP3 group>AOP4 group>AOP2 group>AOP1 group>C group. It can be seen that the addition of Artemisia ordosica polysaccharide can improve the rumen fermentation function under in vitro culture conditions, and the best promotion effect is achieved at an addition dose of 0.3%.

This experiment was conducted to investigate the effects of plant essential oil and bile salt compound preparation on intestinal barrier function of goats. Twenty-four 5-month-old Alxa white cashmere goat rams with body weight of (21.46±2.07) kg were randomly divided into 4 groups with 6 replicates in each group and 1 goat in each replicate. The control group was fed a basal diet, and the experimental groups were fed basal diet supplemental with 5 g/kg compound preparation with medical stone as carrier; among them, the compound preparation in experimental group 1 (T1 group) contained 500 mg plant essential oil (60% artemisia oil, 40% carvacrol+cinnamaldehyde+oregano oil), the compound preparation in experimental group 2 (T2 group) contained 500 mg plant essential oil (60% artemisia oil, 40% carvacrol+cinnamaldehyde+oregano oil) and 500 mg bile salt, and the compound preparation in experimental group 3 (T3 group) contained 500 mg bile salt. The pre-feeding period was 10 days and the feeding period was 60 days. The results showed as follows: 1) compared with the control group, the average daily feed intake of T1 group and T2 group was significantly increased (P<0.05); the feed to gain ratio of T1 group was decreased by 28%, and the feed to gain ratio of T2 group was decreased by 10%. 2) Compared with the control group, the villous height and villous height/crypt depth in jejunum of T1 and T2 groups were significantly increased (P<0.05), and the crypt depth in jejunum of T1 group was significantly decreased (P<0.05); the villous height and villous height/crypt depth in ileum of T1 group were significantly increased (P<0.05), and the crypt depth in ileum of T1 and T2 groups was significantly decreased (P<0.05). 3) Compared with the control group, the mRNA relative expression level of zonula occluden-1 (ZO-1) in cecal mucosa of T1 group was significantly increased (P<0.05); the mRNA relative expression level of Occludin in rumen of T2 and T3 groups was significantly increased (P<0.05), and the mRNA relative expression level of Occludin in ileal mucosa of T1 and T2 groups was significantly increased (P<0.05); the mRNA relative expression level of Claudin-1 in cecal mucosa of T1 and T3 groups was significantly increased (P<0.05); the mRNA relative expression level of farnesoid X receptor (FXR) in liver of T1, T2 and T3 groups was significantly increased (P<0.05). In conclusion, the addition of compound plant essential oil in diet has the best effect on average daily feed intake, feed to gain ratio and intestinal tissue morphology development of goats, and can promote the mRNA expression of intestinal tight junction proteins. The addition of plant essential oil and bile salt compound preparation in diet can increase average daily feed intake and decrease feed to weight ratio to a certain extent of goats, and has a positive effect on the healthy development of the intestine.

This experiment was conducted to study the effects of riboflavin on growth performance, nitrogen metabolism and serum biochemical and antioxidant indices of lambs. Forty-eight 3-month-old purebred Hu male lambs with body weight of (18.80±0.83) kg were randomly assigned to four groups with 12 lambs per group. Lambs in 4 groups were fed basal diets supplemented with 0 (control group), 15 (LRF group), 30 (MRF group) and 45 mg/kg (HRF group) riboflavin, respectively. The pre-experimental period lasted for 15 days, and the experimental period lasted for 70 days. The results showed as follows: 1) the average daily gain of MRF group was significantly higher than that of MRF group and control group (P<0.05), and the feed to gain ratio of MRF group was significantly lower than that of the control group (P<0.05). 2) The digested nitrogen and retained nitrogen of MRF group were significantly higher than those of MRF group and control group (P<0.05), and the apparent digestibility of nitrogen of MRF group was significantly higher than that of the control group (P<0.05). 3) The contents of glucose (GLU)and growth hormone (GH) in serum of LRF, MRF and HRF groups were significantly higher than those of the control group (P<0.05), the serum riboflavin content of MRF and HRF groups was significantly higher than that of the control group (P<0.05), and the serum urea nitrogen (UN) of MRF and HRF groups was significantly lower than that of the control group (P<0.05). 4) The serum total antioxidant capacity (T-AOC) and catalase (CAT) activity of MRF and HRF groups were significantly higher than those of the control group (P<0.05), and the serum malondialdehyde (MDA) content of HRF group was significantly lower than that of the control group (P<0.05). In conclusion, dietary 30 mg/kg riboflavin can improve the growth performance, nitrogen metabolism and serum biochemical and antioxidant indices of lambs.

This experiment was conducted to investigate the effects of cellulase on the nutrients, fermentation quality, rumen degradation rate in vitro and microbial diversity of mixed silage of corn straw and distiller’s grains. Three groups were set, namely control group (CK group), cellulase group (CE group, supplemented with 50 U/g cellulase preparation) and cellulase and starch group (CES group, supplemented with 50 U/g cellulase preparation and 2% starch), respectively, and the silage was fermented for 30 days. The results showed as follows: 1) compared with CK group, the contents of dry matter and crude protein in CE and CES groups were significantly increased (P<0.05), and the water-soluble carbohydrate content in CES group had a trend to be increased (P=0.053). 2) Compared with CK group, the pH in CE and CES groups was extremely significantly decreased (P<0.01), and the pH in CES group was also extremely significantly decreased compared with CE group (P<0.01). Compared with CK group, the lactic acid content and lactic acid to acetic acid ratio in CES group were extremely significantly increased (P<0.01), the ammonia nitrogen to total nitrogen ratio was significantly decreased (P<0.05), the lactic acid bacteria number was extremely significantly increased (P<0.01), and the lactic acid bacteria number in CES group was also extremely significantly increased compared with CE group (P<0.01); the lactic acid content in CE group was significantly increased (P<0.05), the lactic acid to acetic acid ratio tended to be increased (P=0.064), the ammonia nitrogen to total nitrogen ratio tended to be decreased (P=0.089), and the lactic acid bacteria number was significantly increased (P<0.05). 3) Compared with CK group, the dry matter degradation rate in vitro in CE and CES groups was significantly increased (P<0.05), the neutral detergent fiber degradation rate in vitro in CES group was significantly increased (P<0.05), and the neutral detergent fiber degradation rate in vitro in CE group had a trend to be increased (P=0.071). 4) Compared with CK group, Observed_species in CES group were extremely significantly increased (P<0.01), Shannon index had a trend to be increased (P=0.088), Chao1 index and Ace index were extremely significantly increased (P<0.01), and Chao1 index and Ace index in CES group were significantly higher than those in CE group (P<0.05); Observed_species in CE group had a trend to be increased (P=0.079). Compared with CK group, at the phylum level, the Firmicutes relative abundance in CE and CES groups was significantly increased (P<0.05), while the Proteobacteria relative abundance was significantly decreased (P<0.05); at the genus level, the relative abundances of Lactiplantibacillus and Limosilactobacillus in CE and CES groups were significantly increased (P<0.05), while the Lentilactobacillus relative abundance was significantly decreased (P<0.05). In conclusion, adding cellulase and starch after mixing corn straw with distiller’s grains can reduce nutrient loss during silage, improve fermentation quality and rumen degradation rate in vitro, improve microbial community diversity and microbial structure of silage, and the effect of adding cellulase and starch at the same time is better.

The experiment was aimed to study the nutrition of Chaetoceros muelleri and effects of Chaetoceros muelleri on the breeding water quality, growth, non-specific immunity and resistant capability of Litopenaeus vannamei in different addition amount. In this experiment, the nutrition composition of Chaetochetes mouti was detected firstly, and then 0 (control group), 0.5×10⁵(test group Ⅰ), 1.0×10⁵(test group Ⅱ), 2.0×10⁵(test group Ⅲ)and 4.0×10⁵ cell/mL (test group Ⅳ)of Chaetoceros mouterii were added in each group to carry out seedling test from zoea to mysis Ⅱ period. A total of 1.5×10⁵ healthy nauplii of Litopenaeus vannamei in each group was placed in 1 000 L black barrel, with 3 replicates per group. The results showed as follows: 1) the contents of water, corde protein, crude fat and ash were 75.23%, 14.30%, 2.97% and 7.50% in Chaetoceros muelleri, respectively. The contents of essential amino acids accounted for 46.82% of total amino acids, and those of umami amino acids accounted for 40.42% of total amino acids. There were 18 kinds of fatty acids in Chaetoceros muelleri, among which 8 kinds of saturated fatty acids accounted for 39.40% of total fatty acid content and 10 kinds of unsaturated fatty acids accounted for 50.29% of total fatty acid content. 2) Chaetoceros muelleri could improve breeding water quality, promote growth, improve the germination rate of young shrimps, test groups Ⅳ and Ⅲ had obvious advantages, and had significant differences from other groups (P<0.05), but feed difference between those two group was not significant (P>0.05). The diet consumption of test groups decreased with the increase of the supplemental level of Chaetoceros muelleri. Except for test group Ⅰ, the feed consumption of other test groups was significantly different from that of control group (P<0.05). 3) The activities of amylase, lipase and proteinase in the test groups were increased with the increase of the addition of Chaetoceros muellerii, respectively. The amylase activity of larvae in test group Ⅳ was significantly different from that in control group (P<0.05), but there was no significant difference among other groups (P>0.05). Lipase and protease activities of shrimp in test groups were significantly different from those in control group (P<0.05), but there were no significant differences among test groups Ⅱ, Ⅲ and Ⅳ (P>0.05). 4) The total antioxidant capacity (T-AOC) and the activities of superoxide dismutase (SOD) and peroxidase (POD) in the test groups were increased with the increase of the addition of Chaetoceros muellerii, respectively, which were significantly different from the control group (P<0.05), respectively. The activities of acid phosphatase (ACP) and alkaline phosphatase (AKP) in the test groups were no significantly different from the control group (P>0.05). 5) Under the stress of formaldehyde at 3.0×10^-4 mL/L, the survival rate of post-larval in each group gradually decreased with the increase of stress time. After 24 h, the survival rate of larvae in test groups was 11.45%, 22.90%, 24.41% and 37.40% higher than that in control group, respectively, and the difference among groups was significant (P<0.05). Chaetoceros muelleri is suitable initial feeding for shrimp larvae and good feed during seedling raising because of its small size, weak exercise ability and abundant nutrition. Chaetoceros muelleri can reduce the contents of harmful factors such as ammonia nitrogen, nitrite nitrogen and chemical oxygen demand in water, eliminate stress factors and maintain stable water quality and conducive to the growth of shrimp. In summary, Chaetoceros muelleri can improve the activity of digestive enzymes, immune factors and the emergence rate of shrimp post-larvae at 1.0×10⁵ to 2.0×10⁵ cell/mL addition amount of Chaetoceros muelleri.

The aim of this study was to investigate the effects of proline on growth performance, antioxidant capacity and resistance to Aeromonas hydrophila infection of Pelodiscus sinensis. Forty-eight healthy young Pelodiscus sinensis with an initial body weight of about 200 g were randomly divided into control group (P0 group) and proline group (P4 group), which fed diets supplemented with 0 (basal diet) and 40 g/kg proline, respectively, and each group had 3 replicates and each replicate had 8 turtles. The experiment lasted for 42 days. After the feeding experiment, 3 turtles were randomly selected from each group to be intraperitoneally injected with 1 mL Aeromonas hydrophila (Ah) bacteria solution, and labeled as P0+Ah group and P4+Ah group, respectively; another 3 turtles were randomly selected in each group to be intraperitoneally injected with the same amount of sterile normal saline and labeled as P0+NS group and P4+NS group, respectively. After 24 h of challenge, the relevant indices were determined by sampling. The results showed as follows: 1) compared with the control group, the survival rate, weight gain rate and specific growth rate of Pelodiscus sinensis in proline group were significantly increased (P<0.05), but there were no significant differences in hepatosomatic ratio and viscerosomatic ratio (P>0.05). 2) Compared with P0+NS group, the activities of glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) in calipash tissues of Pelodiscus sinensis in P4+NS group were significantly improved (P<0.05), and the production rate of mitochondrial reactive oxygen species (ROS) was significantly decreased (P<0.05). Under Ah stress, compared with P0+Ah group, the activities of GSH-Px and SOD in calipash tissues in P4+Ah group were significantly increased (P<0.05), while the production rate of mitochondrial ROS was significantly decreased (P<0.05). 3) Compared with P0+NS group, the content of proline and hydroxyproline in calipash tissues of Pelodiscus sinensis in P4+NS group was significantly improved (P<0.05). Under Ah stress, compared with P0+Ah group, the contents of proline and hydroxyproline in calipash tissues in P4+Ah group were significantly increased (P<0.05). 4) Compared with P0+NS group, the mRNA relative expression levels of collagen type Ⅰ A1 (COL1A1), collagen type Ⅰ A2 (COL1A2), prolyl 4-hydroxylase A1 (P4HA1), prolyl 4-hydroxylase A3 (P4HA3), transforming growth factor-β2 (TGF-β2) and transforming growth factor-β3 (TGF-β3) in calipash tissues of Pelodiscus sinensis in P4+NS group were significantly increased (P<0.05), and the mRNA relative expression levels of tissue metalloproteinase inhibitor 2 (TIMP2) and tissue metalloproteinase inhibitor 4 (TIMP4) were significantly decreased (P<0.05). Under Ah stress, compared with P0+Ah group, the mRNA relative expressions of COL1A1, COL1A2, P4HA1, P4HA3, TGF-β2, TGF-β3, matrix metalloproteinase 1 (MMP1), matrix metalloproteinase 2 (MMP2), TIMP2 and TIMP4 in calipash tissues in P4+Ah group were significantly increased (P<0.05). 5) Histological studies had shown that the collagen layer in calipash tissues of Pelodiscus sinensis in P4+NS group was clearly delimited and the collagen fibers were orderly arranged, while that in P4+Ah group tended to be blurred and disordered, and the collagen fibers tended to be degraded internally. In conclusion, dietary supplementation of 40 g/kg proline can improve the growth performance of young Pelodiscus sinensis, and also play a role in resisting Ah stress by enhancing the activity of antioxidant enzymes, reducing ROS production and balancing collagen metabolism.

This experiment was conducted to study the effects of Zanthoxylum schinifolium leaf powder on the growth performance, small intestinal development, slaughter performance and meat quality of meat rabbits. Six hundred 28-day-old “Shuxing No.1” commercial meat rabbits with similar body weight were randomly divided into 5 groups with 6 replicates in each group and 20 rabbits (half male and half female) in each replicate. Rabbits in the 5 groups were fed diets containing 0 (control group), 3%, 6%, 9% and 12% Zanthoxylum schinifolium leaf powder, respectively. The pre-feeding period was 7 days and the trial period was 42 days. The results showed as follows: 1) with the increase of Zanthoxylum schinifolium leaf powder supplemental level, the average daily feed intake and average daily gain of rabbits showed a trend of first increasing and then decreasing, and the 6% group had the highest values, which were significantly higher than those in the control group and other experimental groups (P<0.05); the feed to gain ratio showed a trend of first decreasing and then increasing, and the 12% group was significantly higher than the control group, 3% group and 6% group (P<0.05); the diarrhea rate and mortality showed a trend of decreasing gradually, and the 12% group was significantly lower than the control group (P<0.05). 2) The ratio of villus height/crypt depth of duodenal mucosa in the 6% group was significantly lower than that of the control group (P<0.05); the amylase activity of jejunum in 9% group and 12% group was significantly lower than that of the control group (P<0.05); the trypsin activity of jejunum in 12% group was significantly lower than that of the control group (P<0.05). 3) With the increase of Zanthoxylum schinifolium leaf powder supplemental level, the live weight before slaughter, half eviscerated weight, full eviscerated weight, half eviscerated dressing percentage and full eviscerated dressing percentage showed a trend of first increasing and then decreasing, the slaughter performance of 6% group was the best, followed by 3% group, control group, 9% group and 12% group. 4) With the increase of Zanthoxylum schinifolium leaf powder supplemental level, the pH_{24 h}, ether extract and inosinic acid contents of longissimus dorsi increased firstly and then decreased, the redness (a^*) value increased gradually, and the drip loss decreased firstly and then increased. Among them, the 6% group had the highest pH_{24 h}, ether extract and inosinic acid contents, and the lowest drip loss. In summary, adding an appropriate proportion of Zanthoxylum schinifolium leaf powder in the diet of rabbits can increase the feed intake and growth rate of meat rabbits, promote small intestinal mucosa development, increase jejunal digestive enzyme activities, improve slaughter rate and meat quality, and the appropriate supplemental level is 6%.

This experiment was conducted to study the effects of fermented concentrate on dietary nutrient digestibility, intestinal morphology, gastrointestinal pH and cecal microbial diversity of meat rabbits. One hundred and sixty healthy 35-day-old Ira meat rabbits with similar body weight were randomly divided into 4 groups with 8 replicates in each group and 5 rabbits in each replicate. The control group (CON) was fed a basal diet, and the test groups were fed 5% (T1 group),10% (T2 group) and 15% (T3 group) fermented concentrate replaced the basal diet concentrate part (corn, wheat middlings and soybean meal), respectively. The pre-test period was 7 days, and the test period was 28 days, with the digestion test was 7 days. The results showed as follows:1) compared with the CON group, the dietary acid detergent fiber (ADF) digestibility of T1, T2 and T3 groups was significantly increased (P<0.05), the digestibility of ether extract (EE), crude fiber (CF), neutral detergent fiber (NDF) and calcium (Ca) of T2 and T3 groups were significantly increased (P<0.05), and the phosphorus (P) digestibility of T3 group was significantly increased (P<0.05). 2) Compared with the CON group, the ileal crypt depth of T1 group was significantly decreased (P<0.05), the cecal mucosal thickness of T3 group was significantly decreased (P<0.05), and the gastric pH of T1, T2 and T3 groups had a decreasing trend (0.05≤P<0.10). 3) At the phylum level, compared with the CON group, the cecal Firmicutes relative abundance of T1 group was significantly increased (P<0.05), the cecal Bacteroidetes relative abundance of T1 and T3 group was significantly decreased (P<0.05), and the cecal Cyanobacteria of T3 group was significantly increased (P<0.05). At genus level cecal, compared with the CON group, the relative abundances of Ruminococcaceae_unclassified, Lachnospiraceae_unclassified and Acetivibrio in cecum of T1 and T2 group were significantly increased (P<0.05), and the cecal Alistipes relative abundance of T1 and T3 group was significantly decreased (P<0.05). In conclusion, dietary fermented concentrate can reduce gastrointestinal pH to a certain extent, improve the intestinal morphology, regulate the cecal microbial balance, thus increase dietary nutrient digestibility of weaned rabbits.

The purpose of this experiment was to study the effects of dietary Clostridium butyricum on cecal flora structure and fecal short chain fatty acids (SCFAs) contents of Ira rabbits. A total of 216 weaned male Ira rabbits at 28 days of age with similar body weight were randomly divided into 4 groups with 6 replicates in each group and 9 rabbits in each replicate. The control group (CG group) was fed a basal diet, and the experimental groups were fed basal diets supplemented with 200 (LC group), 400 (MC group) and 600 mg/kg (HC group) Clostridium butyricum, respectively. The pre-experimental period lasted for 4 days, and the experimental period lasted for 35 days. The results showed as follows: 1) the dominant bacteria in caecum in all groups were Firmicutes, Bacteroides, Verrucomicrobia and Actinobacia. 2) At 32 and 39 days of age, the cecal Actinobacia relative abundance of MC group was significantly lower than that of CG group (P<0.05). At 60 and 67 days of age, the cecal Verrucomicrobia relative abundance of LC, MC and HC groups was significantly lower than that of CG group (P<0.05). 3) At 53 and 67 days of age, the content of acetic acid and propionic acid in feces of experimental groups were increased compared with CG group. At 53 days of age, the fecal butyric acid content of LC group was significantly lower than that of CG group (P<0.05); at 67 days of age, the fecal isovaleric acid of LC group was significantly lower than that of CG group (P<0.05). 4) At 53 days of age, the Bacteroides relative abundance was significant positively correlated with the acetic acid content (P<0.05); the Ruminococcaceae_UCG-013 relative abundance was significant negatively correlated with the propionic acid content (P<0.05), and extremely significant negatively correlated with the butyric acid content (P<0.01). At 67 days of age, the Ruminococcaceae_NK4A214_group relative abundance was significant negatively correlated with the acetic acid content (P<0.05), and the Ruminococcaceae_UCG-013 relative abundance was significant negatively correlated with the propionic acid and butyric acid contents (P<0.05). To sum up, dietary Clostridium butyricum can change the cecal flora structure and microbial diversity, change the fecal SCFAs contents, and the cecal flora relative abundance is correlated with the fecal SCFAs contents.

This experiment was aimed to study the mechanism of dietary vitamin E (VE) regulating metabolism of fatty acids in goat subcutaneous fat by RNA-Seq technique. Forty weaned male Lingqiu Qingbei goats with similar body weight [approximately (16.39±0.59) kg, P>0.05] and good health were randomly divided into four groups, and each group had 10 replicates. Each group of goats were fed a basal diet added with 0 (CON group), 100 (VE₁₀₀ group), 250 (VE₂₅₀ group) and 500 IU/(goat ·d) VE (DL-α-tocopheryl acetate) (VE₅₀₀ group). The pre-trial period lasted for 10 days and the experimental period lasted for 92 days. The results showed as follows: 1) dietary VE had no significant effect on growth performance of goats (P>0.05). 2) Compared with CON group, VE content in the goat subcutaneous fat increased significantly after dietary VE supplementation (P<0.05). 3) Compared with CON group, the total saturated fatty acid content decreased significantly (P<0.01) and the total monounsaturated fatty acid content increased significantly (P<0.05) in VE₅₀₀ group. 4) A total of 866 differentially expressed genes(DEGs) were screened in CON group and VE₅₀₀ group, which 429 genes were up-regulated, while 437 genes were down-regulated. The GO function analysis showed that DEGs were highly enriched in the biological processes such as lipid metabolic process, fatty acid synthase activity, fatty acid elongase activity. The KEGG pathway were significantly enriched to 62 pathways, in which unsaturated fatty acid biosynthesis and fatty acid biosynthesis were the main metabolic pathways, peroxisome proliferator activated receptor (PPAR) signaling pathway, mitogen activated protein kinase (MAPK) signaling pathway and calcium signaling pathway played an important role in fatty acid metabolism. 5)Compared with the CON group, the relative expression levels of extra-long chain fatty acid extentase 3 (ELOVL3) and extra-long chain fatty acid extentase 5 (ELOVL5) genes, which were key enzymes for fatty acid metabolism were significantly up-regulated (P<0.05), while the relative expression levels of extra-long chain fatty acid extentase 7 (ELOVL7), extra-long chain fatty acid extentase 6 (ELOVL6) and fatty acid synthase (FASN) genes were significantly down-regulated (P<0.05). In conclusion, dietary supplemental 500 IU/(goat·d) VE can improve the fatty acid composition of goats. This study identify the important genes and signal pathways related to VE regulation of fatty acid metabolism, which provides a theoretical basis for further understanding the molecular mechanism of improving the subcutaneous fatty acid composition of goats through nutritional regulation.

This study aimed to investigate the effects of different doses of linoleic acid and oleic acid supplementation on triglyceride synthesis in mammary epithelial cells of lactating dairy cows. Bovine mammary epithelial cells were used as the research object. The experiment consisted of two parts. In the first experiment, the control group was not supplemented with fatty acids, and the experimental groups were supplemented with 100 μmol/L oleic acid, 100 μmol/L linoleic acid, 100 μmol/L oleic acid + 100 μmol/L linoleic acid, respectively. In the second experiment, the control group was supplemented with 100 μmol/L oleic acid alone, and the experimental groups were supplemented with 100 μmol/L oleic acid and mixed with 25, 50 and 75 μmol/L linoleic acid. Each group was repeated 6 times. The viability of mammary epithelial cells, the relative content of triglyceride, and the mRNA relative expression levels of genes related to milk fat synthesis were measured. Results showed as follows: 1) the results of experiment 1 showed that compared with control group, supplemented with oleic acid and linoleic acid alone or in combination significantly increased the mammary epithelial cell viability (P<0.05); supplemented with oleic acid or linoleic acid significantly increased the relative content of triglyceride (P<0.05), while the mixed supplementation did not affect the relative content of triglyceride (P>0.05); supplemented with oleic acid alone significantly increased the mRNA relative expression levels of acetyl-CoA carboxylase (ACACA), 1-monoacylglycerol-3-phosphate acyltransferase 6 (AGPAT6), glycerol-3-phosphate acyltransferase (GPAM) (P<0.05). The mRNA relative expression levels of AGPAT6 and sterol regulatory element binding protein 1 (SREBF1) were significantly increased by supplementing of linoleic acid alone (P<0.05). Mixed supplemented with equal amounts of oleic and linoleic acid significantly reduced the mRNA relative expression levels of ACACA, SREBF1, differentiation antigen cluster 36 (CD36), acyl-CoA synthetase 1 (ACSL1) (P<0.05). 2) The results of experiment 2 showed that supplemented with fixed amount of oleic acid and increasing amount of linoleic acid had no effect on the relative content of triglyceride (P>0.05). Supplemented with 100 μmol/L oleic acid and 25 μmol/L linoleic acid significantly increased the mRNA relative expression levels of ACACA and SREBF1 (P<0.05) and significantly decreased the mRNA relative expression level of fatty acid binding protein 3 (FABP3) (P<0.05). Supplemented with 100 μmol/L oleic acid and 50 μmol/L linoleic acid significantly increased the mRNA relative expression levels of fatty acid synthetase (FASN), stearyl CoA desaturase (SCD), CD36, AGPAT6, diacylglyceryl transferase 1 (DGAT1), GPAM and phospholipid acid phosphatase (LPIN1) (P<0.05) and significantly decreased the mRNA relative expression level of peroxisome proliferator activated receptor γ (PPARG) (P<0.05). Supplemented with 100 μmol/L oleic acid and 75 μmol/L linoleic acid significantly increased the mRNA relative expression levels of ACACA, FASN, SREBF1 and PPARG (P<0.05), and significantly decreased the mRNA relative expression level of AGPAT6 (P<0.05). These results suggest that the supplementation amount of linoleic acid is an important factor in regulating milk fat synthesis in mammary epithelial cells when linoleic acid and oleic acid are supplemented in combination.

The aim of this experiment was to investigate the effects of subacute rumen acidosis (SARA) on the mRNA relative expression levels and protein relative expression levels of volatile fatty acid (VFA) absorption and metabolism related genes in ruminal epithelium of dairy goats. Twelve lactating Saanen dairy goats with similar body weight [(62.13±4.76) kg] were installed permanent rumen fistulas and randomly divided into two groups with 6 goats per group. Goats in the control group were fed a basal diet, and dietary non-fibrous carbohydrate/neutral detergent fiber (NFC/NDF) was 1.15; the others in SARA group was fed experimental diets to establish SARA model, and dietary NFC/NDF were 1.15, 1.49, 2.12 and 2.66, respectively. The trial period was 60 days. At the end of the experiment, dairy goats were slaughtered and collected the rumen epithelial tissues from ventral sac. The mRNA relative expression levels and protein relative expression levels of VFA absorption and metabolism related genes in ruminal epithelium were detected by real-time PCR (RT-PCR) and Western blotting methods. The correlation between rumen fermentation parameters, VFA absorption rate of ruminal epithelium and mRNA relative expression levels of VFA absorption and metabolism related genes was analyzed. The results showed as follows: 1) compared with the control group, the mRNA relative expression levels of Na⁺/H⁺ exchanger 1 (NHE1), acyl-CoA short chain synthetase 2 (ACSS2), 3-hydroxy-3-methylglutaryl-CoA synthetase 1 (HMGCS1), 3-hydroxy-3-methylglutaryl-CoA synthetase 2 (HMGCS2) and 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) in ruminal epithelium of SARA group were significantly up-regulated (P<0.01), and the mRNA relative expression levels of Na⁺/H⁺ exchanger 3 (NHE3), monocarboxylate transporter 1 (MCT1) and down-regulated adenoma carrier (DRA) were significantly up-regulated (P<0.05). 2) Compared with the control group, the relative protein expression levels of NHE1, NHE3, Na⁺/H⁺ exchanger 4 (NHE4), monocarboxylate transporter 2 (MCT2), anion exchanger 2 (AE2), Na⁺/K⁺-ATPase, ACSS2, acyl-CoA short-chain synthase 3 (ACSS3), 3-hydroxy-3-methylglutaryl-CoA lyase (HMGCL) and acetyl-CoA acetyltransferase 1 (ACAT1) in ruminal epithelium of SARA group were significantly up-regulated (P<0.05). In conclusion, SARA can increase the mRNA relative expression levels of NHE1, NHE3, MCT1, DRA, ACSS2, HMGCS1, HMGCS2 and HMGCR in ruminal epithelium and the protein relative expression levels of NHE1, NHE3, NHE4, MCT2, AE2, Na⁺/K⁺-ATPase, ACSS2, ACSS3, HMGCL and ACAT1, there by accelerate the absorption and metabolism of VFA in ruminal epithelium and relieve the damage to the body of SARA.

In the present study, the rat intestinal epithelial cells (IEC-6 cells) were investigated to evaluate the effects of docosahexaenoic acid (DHA) and DHA-enriched Schizochytrium oil (SZO) on the prevention and alleviation of oxidative damage induced by hydrogen peroxide (H₂O₂) in IEC-6 cells. At first, the IEC-6 cells were incubated with 0, 5, 10, 20, 40 and 80 μg/mL of DHA and SZO for 24 and 48 h to screen the optimal additive concentration and culture time by measuring the cell proliferation index with methyl thiazolyl tetrazolium (MTT) cell viability test kit. After that, in the H₂O₂ induction before and after, the DHA and SZO were added to the cell culture medium with optimal additive concentration. At the end of the culture, the cells and medium supernatant were collected to test the antioxidant index and inflammatory factors expression level, as well as intracellular nuclear factor E2-related factor 2 (Nrf2) and nuclear factor-κB (NF-κB) signaling pathways expression. The results showed that the optimal additive concentration and culture time of DHA were 40 μg/mL and 24 h, respectively. The DHA and SZO treatment increased the total antioxidant capacity and activities of antioxidant enzymes (superoxide dismutase, catalase and glutathione peroxidase) of H₂O₂-induced IEC-6 cells, decreased the contents of reactive oxygen species and malondialdehyde, and the antioxidant enzyme activities of alleviation effect were significantly higher than those of prevention effect (P<0.05). The Western blot results indicated that the DHA and SZO treatment decreased the protein expression levels of NF-κB, tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) of H₂O₂-induced IEC-6 cells, and increased the Nrf2 protein expression level. Otherwise, the TNF-α protein expression level of alleviation effect of SZO treatment was significantly lower than that of prevention effect (P<0.05). In summary, DHA and SZO can enhance antioxidant and anti-inflammatory ability by activating Nrf2 and inhibiting NF-κB signaling pathways, to prevent and alleviate H₂O₂-induced oxidative stress in IEC-6 cells, and the alleviation effect against oxidative damage of SZO is higher than the preventive effect.

The aim of this experiment was to investigate the effects of different concentrations of glutamine (Gln) and different starvation time treatment on the degree of autophagy in mouse liver cells, and to provide basic data to support the application of Gln on domestic animals. In this experiment, mouse liver cell line (NCTC1469) was selected as the test material and cultured in DMEM high sugar medium until the density was about 90%. For Gln concentration treatment, serum-free starvation culture was performed for 12 h. After 12 h, the cells were divided into 8 treatments with Gln concentrations of 0, 2%, 4%, 8%, 16%, 32%, 64% and 100% for 12 h. For starvation time treatment, serum-free starvation culture was performed for 12 h. After 12 h, the cells were divided into 8 treatments with starvation times of 0, 0.5, 1.0, 2.0, 4.0, 8.0, 12.0 and 24.0 h for Gln-free treatment. The results showed that the mammalian target protein of rapamycin (mTOR) pathway protein expression all showed an increasing trend with the increase of Gln concentration in Gln treatment, and the protein expression levels of eukaryotic initiation factor 2α (eIF2α), ULK1-555 and the ratio of microtubule-associated protein 1 light chain 3B (LC3B) type Ⅱ to type Ⅰ ( LC3BⅡ/Ⅰ), and transcription activation factor 4 (ATF4) all showed a decreasing trend with increasing Gln concentration, and R² were all greater than 0.5; ATF4, P62 and mTOR protein expression levels all showed an increasing trend with the increase of starvation time, with R² was greater than 0.5; in the Gln concentration treatment, the intracellular contents of histidine (His), glycine (Gly), threonine (Thr), lysine (Lys), tyrosine (Tyr), methionine (Met), valine (Val), isoleucine (Ile), leucine (Leu), phenylalanine (Phe) and tryptophan (Trp) were significantly higher at 0 Gln concentration than other treatments (P<0.05); the intracellular contents of serine (Ser), Thr, Tyr, Met, Val, Ile, Leu, Phe and Trp increased significantly (P<0.05) with increasing starvation time in the time treatment. In conclusion, mouse liver cell line (NCTC1469) is treated with different concentrations of Gln for 12 h, the increase of Gln concentration inhibits autophagy; after different time starvation treatments, the GCN2 pathway regulate cellular uptake of exogenous amino acids to reactivate mTOR, overall the degree of autophagy is diminished with increasing starvation time.

In order to explore the antioxidant effect of flavonoids from Ulmus pumila fruits on chronic sleep deprivation mice, forty-two 4-week-old specific pathogen free (SPF) male ICR mice were randomly divided into 7 groups according to body mass, they were blank control group, model control group, carboxymethylcellulose sodium (CMC-Na) control group, positive control group, and flavone high-, medium- and low-concentration groups. There was no significant difference in body mass among the groups (P>0.05). Except the blank control group, the other 6 groups of mice were used to establish chronic sleep deprivation model, and the chronic sleep deprivation model was established by using the modified multi water platform sleep deprivation method. After successful establishing the model, mice were gavaged for 4 weeks according to the following design: flavonoids high-, medium- and low- concentration groups were gavaged with 30, 60 and 120 mg/(kg BW·d) Ulmus pumila fruits flavone, blank control group was gavaged with the same amount of normal saline, positive control group was gavaged with 300 mg/(kg BW·d) melatonin, model control group was gavaged with the same amount of normal saline, CMC-Na control group was gavaged with the same amount of 0.5% CMC Na solution. The superoxide dismutase (SOD), glutathione peroxidase (GPX) activities, total antioxidant capacity (T-AOC) and malondialdehyde (MDA) content in liver, brain and duodenum of mice were measured by kits, and the mRNA relative expression levels of antioxidant genes SOD-1, SOD-2, GPX-1 and GPX-4 in liver, brain and duodenum of mice were measured by real-time fluorescent quantitative PCR method. The results showed that high-, medium- and low-concentrations of flavonoids from Ulmus pumila fruits could significantly increase the activities of SOD, GPX and T-AOC in brain, liver and duodenum of mice (P<0.05), significantly reduce the content of MDA in brain, liver and duodenum of mice (P<0.05), and significantly increase the mRNA relative expression levels of SOD-1, SOD-2, GPX-1 and GPX-4 in brain, liver and duodenum of mice (P<0.05). In conclusion, flavonoids from Ulmus pumila fruits can significantly improve the activities and related gene expression of antioxidant enzymes, and reduce the oxidative stress damage in chronic sleep deprivation mice.

This experiment was conducted to study the effects of Apriona swainsoni (A. swainsoni) larvae on body weight, gastrointestinal motility function and gastric hormone levels of mice with functional dyspepsia. After adaptive feeding for 5 days, ninety specific pathogen free (SPF) grade ICR mice were randomly divided into normal group, model group, domperidone group (10 mg/kg), low A. swainsoni larvae low (4%), medium (8%) and high concentration group (12%), with 15 mice per group. Except for the normal group, the FD mouse model of the other groups was established by irregular feeding combined with intraperitoneal injection of L-arginine (L-Arg). After the successful establishment of FD mouse model, the mice in the domperidone group (10 mg/kg BW domperidone), and A. swainsoni larvae low (4% A. swainsoni larvae suspension), medium (8% A. swainsoni larvae suspension) and high concentration (12% A. swainsoni larvae suspension) groups were given the corresponding drugs with the intragastric volume 0.2 mL per day, normal group and model group were given the same volume of normal saline. The body weight at the beginning of modeling, the end of modeling and the end of intervention of the mice was recorded. After 7 days of continuous intragastric administration, mice were killed after intragastric administration of semi-solid paste with carbon powder, and the whole stomach and small intestine of mice were removed to calculate the gastric emptying rate and intestinal propulsion rate; the levels of serum gastrin (GAS) and motilin (MTL) in mice were determined by enzyme-linked immunosorbent assay (ELISA); the pathological changes of gastric tissue of mice were observed by hematoxylin-eosin (HE) staining. The results showed that the body weight, gastric emptying rate and intestinal propulsion rate of mice in the model group were significantly decreased (P<0.05), and the levels of GAS and MTL in serum were significantly decreased compared with the normal group (P<0.05); compared with the model group, the body weight, gastric emptying rate and small intestinal propulsion rate in the A. swainsoni larvae low, middle and high concentration groups were significantly increased (P<0.05), the levels of GAS and MTL in serum were significantly increased (P<0.05), meanwhile, the body weight of mice was significantly increased (P<0.05). There was no difference in gastric histopathology among all groups. In conclusion, irregular diet combined with intraperitoneal injection of L-Arg can successfully establish FD mouse model; A. swainsoni larvae can promote gastrointestinal motility and improve FD of mice, and its mechanism may be related to the increase of serum GAS and MTL levels.

This experiment was conducted to study the spectral characteristic of pork in different parts and its relationship with meat color. The spectral datas and corresponding meat color values of pork in different parts were measured by ASD-2000 spectrometer and CR-400 colorimeter, to forming characteristic spectra of pork in different parts. Through random forest, maximum mutual information index and optimal index factor, selected the 473 and 1 078 nm bands that reflect the largest differences in meat color. Using the combination of these bands, the pork color ratio index (PCRI) was proposed, and the correlation between PCRI and chromaticity index and browning index was analyseed. The results showed that the spectral characteristic of pork belly was easy to distinguish, and the spectral characteristic of tenderloin and leg meat were slightly similar, but the difference between the two can be effectively distinguished by PCRI. There was a significant negative correlation between PCRI and chemical chromaticity index of tenderloin and leg meat (P<0.05), and there was a significant negative correlation between PCRI and browning index of tenderloin (P<0.05). In summary, we obtained the spectral characteristic of pork in different parts based on its spectral data, and proposed the FCRI, and there is a significant negative correlation between PCRI chemical chromaticity index and browning index of pork.

This experiment mainly explored the effects of different proportion of defective pear on quality, microbial diversity and aerobic stability of reed straw silage. The mixed silage was carried out according to the mass ratio of defective pear and reed straw. The ratios of reed straw to defective pear were 10∶0, 9∶1, 8∶2, 7∶3, 6∶4, 5∶5, 4∶6,3∶7, 2∶8 and 1∶9. After 60 days of silage, opened the tank, measured the nutritional components before and after silage, identified the sensory quality, fermentation quality and microbial diversity of the silage, comprehensively evaluated and selectd the five groups of better proportions, and measured the pH and the number of lactic acid bacteria, yeast and mold under the aerobic exposure conditions. The results showed as follows: with the increase of the proportion of defective pear, the contents of lactic acid, acetic acid and soluble sugar in the silage gradually increased (P<0.05), while the pH, ammonia nitrogen, neutral detergent fiber and acid detergent fiber contents gradually decreased (P<0.05); the comprehensive score was excellent except that the silage without defective pear was good. At the phyla level, the dominant phyla of each group was Firmicutes, followed by Proteus; at the genus level, the dominant genera in each group were Lactobacillus and Leuconostoc, and when the ratio of reed straw to defective pear was 6∶4, the relative abundance of Lactobacillus reached the highest, 62.77%. After aerobic exposure, the pH, the number of yeast and mold gradually increased, and the number of lactic acid bacteria gradually decreased. When the ratio of reed straw to defective pear was 7∶3 and 6∶4, the aerobic stability was good. In conclusion, when the ratio of reed straw to defective pear is 6∶4, and the quality of silage is the best.

The purpose of this experiment was to optimize the fermentation and enzymatic hydrolysis conditions for soybean hull, and to explore the effects of fermentation and enzymatic hydrolysis on the nutrient composition and microbial community of soybean hull by biomimetic in vitro, and to evaluate the improvement effects of fermentation and enzymatic hydrolysis on the nutritional value of soybean hull. An orthogonal test was used to optimize the fermentation and enzymatic hydrolysis conditions for soybean hull, and the fermentation temperature was 33, 35 and 37 ℃, the ratio of material to water was 1.0∶1.9, 1.0∶2.0 and 1.0∶2.1, the fermentation time was 5, 6 and 7 d, and the ratio of cellulase to xylanase was 1.0∶1.5, 1.0∶2.0 and 1.0∶2.5, respectively. Then, the improvement of nutritional value of soybean hull under the optimal fermentation conditions was tested, and the in vitro digestion and fermentation of soybean hull after fermentation and enzymatic hydrolysis was evaluated by simulating the environment of pig stomach, small intestine and colon. In vitro simulated digestion experiment was divided into two groups which were untreated soybean hull group (control group) and bacterial and enzyme treated soybean hull group (fermentation and enzymatic hydrolysis group), with 4 replicates in each group. The results showed as follows: 1) the optimal fermentation conditions determined by orthogonal test were fermentation temperature 33 ℃, ratio of material to water 1.0∶2.1, fermentation time 6 d and ratio of cellulase to xylanase 1.0∶2.5. 2) Under the optimal fermentation and enzymatic hydrolysis condition, compared with the control group, the contents of crude protein, reducing sugar and lactic acid in fermentation and enzymatic hydrolysis group were significantly increased (P<0.05), while the contents of crude fiber, neutral detergent fiber and acid detergent fiber were significantly decreased (P<0.05), and the urease activity and contents of glycinin and β-conglycinin were also significantly decreased (P<0.05). 3) Compared with the control group, the in vitro digestibilities of dry matter and crude protein of soybean hull in fermentation and enzyme hydrolysis group was significantly increased (P<0.05); the contents of acetic acid, propionic acid, isobutyric acid and total short-chain fatty acid in fermentation broth of fermentation and enzyme hydrolysis group were significantly decreased (P<0.05), while the pH was significantly increased (P<0.05). 4) Compared with the control group, the Chao1 index of microbial community in the in vitro fermentation system in fermentation and enzyme hydrolysis group was significantly increased (P<0.05), indicating that the microbial richness of the fermentation solution was significantly increased by fermentation and enzymatic hydrolysis; the relative abundances of cellulase-producing bacteria and bacteria associated with butyric acid, propionic acid and isobutyric acid production in fermentation and enzyme hydrolysis group were significantly decreased (P<0.05), while the relative abundance of bacteria associated with hydrogen metabolism was significantly increased (P<0.05). The results suggest that the combination of bacterial fermentation and enzymatic hydrolysis can significantly improve the nutritional value of soybean hull.

The objective of this study was to isolate and characterize lactic acid bacteria with probiotic potential in Alopex lagopus’s gut, and evaluate its probiotic function evaluation in vitro. The isolated strain identified by physiological, biochemical and 16S rRNA identification, measured its growth curve, acid production and acid resistance curves, bile salt tolerance and survival rate in artificial gastric juice and artificial intestinal juice were measured, the antibacterial activity and antibiotic sensitivity of the bacteria were detected by oxford cup agar diffusion test and disk diffusion test, respectively. Finally, twenty female Kunming mice were randomly divided into two groups, the control group was given normal saline intragastrically, and the experimental group was given Lactobacillus salivarius (1×10⁹ CFU/mL), the experiment lasted for 7 days. The results showed that the strain was named Lactobacillus salivarius ZJBF005 according to 16S rRNA and physiological and biochemical identification results, it had a strong acid-producing ability and growth rapidly in the MRS medium; it could maintain good growth in the culture-medium with pH 4 to 7, while couldn’t grow in the culture-medium less than pH 2; the survival rate after incubation in artificial gastric juice and artificial intestinal juice for 3 h were 40.96% and 86.70%, respectively; it could grow in 0.2% bile salt environment; it could inhibit the growth of Salmonella and Staphylococcus aureus; it was not sensitive to antibiotics such as tetracycline, gentamicin, vancomycin, fosfomycin, azithromycin, trimethoprim and metronidazole, etc; the body weight change of mice after intragastric administration was normal, no death, and no pathological change in autopsy. In conclusion, the Lactobacillus salivarius ZJBF005 in healthy Alopex lagopus’s gut has pretty probiotic properties, it can be preliminarily determined as probiotic candidates.

The objective of this study was to evaluate feeding value of different grades of whole-plant corn silage by in vitro gas production method, and to learn the gas production parameters, nutrient degradation rate and fermentation parameters for 30 h. Samples were randomly selected from each of the five grades in the sample bank of the National Grain-to-Feed Whole-Crop Corn Silage Quality Grading Score Index (CSQS) study, for a total of 25 samples. The results showed as follows: 1) there was a significant difference in gas production among the 5 grades of whole-plant corn silage (P=0.06), and the highest gas production was found in grade 1 of whole-plant corn silage. 2) The in vitro dry matter degradation rate (IVDMD), ammonia nitrogen (NH₃-N), acetic acid and propionic acid contents were significantly different among grades of whole-plant silage (P<0.05). There was a trend of significant difference (P=0.07) in the in vitro neutral detergent fiber degradation rate (IVNDFD) among the 5 grades of whole-plant corn silage, respectively. The highest values of IVDMD, IVNDFD, in vitro acid detergent fiber degradation rate (IVADFD), the highest contents of acetic acid and propionic acid and the lowest NH₃-N content were all found in CSQS grade 1 whole-plant corn silage. From the CSQS grades 1 to 5, the values of IVDMD, IVNDFD and IVADFD, the contents of acetic acid and propionic acid decreased linearly (P<0.05), and the content of NH₃-N increased linearly (P=0.06).There was no difference in acetate/propionate among different grades (P>0.05). In summary, the higher the grade of CSQS, the worse the quality and feeding value of whole-plant corn silage.

This experiment was conducted to investigate the effects of gallic acid on nutrient composition and silage quality of whole-plant corn silage. Gallic acid was supplemented to the crushed whole-plant corn material with 0 (control), 0.1%, 0.3%, 0.5%, 0.7% and 0.9%, and stored in silage bag sealed for 110 days to evaluate the silage quality by multiple test, principal component analysis and cluster analysis. The results showed as follows: 1) in terms of nutrient composition, compared with the control group, the contents of dry matter, crude protein and water-soluble carbohydrate of whole-plant corn silage in gallic acid supplemental groups were significantly increased (P<0.05), while the contents of neutral detergent fiber, acid detergent fiber, acid detergent lignin, cellulose, hemicellulose and holocellulose were significantly decreased (P<0.05). In terms of silage quality, compared with the control group, the pH of whole-plant corn silage in 0.5%, 0.7% and 0.9% gallic acid supplemental groups was significantly decreased (P<0.05). The lactic acid content in all gallic acid supplemental groups was significantly increased (P<0.05), the ammonia nitrogen to total nitrogen ratio was significantly decreased (P<0.05), and Fisher score was significantly increased (P<0.05). 2) Compared with the control group, the supplementation of 0.5% to 0.9% gallic acid significantly decreased the biodegradation potential of whole-plant corn silage (P<0.05), and significantly increased the relative feeding value (P<0.05). 3) Three principal components were extracted from the principal component analysis, and the cumulative contribution rate was 88.123%; the principal component comprehensive evaluation and one-way analysis of variance showed that 0.5%, 0.7% and 0.9% gallic acid supplemental groups ranked higher than the other groups, and were significantly higher than the other groups (P<0.05). 4) The groups were divided into three groups by cluster analysis, among which the first group was 0.5%, 0.7% and 0.9% gallic acid supplemental groups, and the silage quality was better; the second group was 0.1% and 0.3% gallic acid supplemental groups, followed by silage quality; and the third group was the control group, the silage quality was average. The results of cluster analysis were consistent with those of principal component analysis. In conclusion, the supplementation of gallic acid can effectively improve the silage quality and relative feeding value of whole-plant corn silage. From the comprehensive consideration of production cost and silage quality, the optimal supplemental concentration of gallic acid is 0.5%.