Oxidative damage induced by oxygen radicals is the major factor to accelerate apoptosis and to make tissue damage and to suffer from diseases. Using antioxidants is effective for scavenging excess free radicals, preventing lipid peroxidation, protecting the natural structure and function of mitochondria, and further reducing morbidity of cancer, arteriosclerosis, diabetes and so on. As one type of natural antioxidants, animal-derived antioxidative peptides have become the hotspot for its abundant sources, high safety and absorption easily. This paper summarized species, structure and biological functions of animal-derived antioxidative peptides. It also put emphasis on discussing the functional properties and relationship between the structure and the functions, analyzing the difficulties of current antioxidant peptide researches and further predicting its application prospects in the field of medicine and food as well as animal feeding.

This study was conducted to investigate the effects of selenium (Se) and vitamin E on performance and blood biochemical indices of dairy cows. Fifty-four Holstein dairy cows (60 to 100 days after calving) were selected and assigned to nine groups by unit block method based on milk yield and parity with 6 cows in each group. There were 2 stages with 8 experimental groups and 1 calibration group per stage, and the calibration group was fixed. Se and vitamin E were added according to a 4×4 two-factor design. Supplemental levels of Se were 0, 0.1, 0.2 and 0.3 mg/kg, and those of vitamin E were 0, 30, 60 and 90 IU/kg, respectively. There was 16 diets in all, and they were represented in 0/0, 0.1/0, ……, 0.2/90 and 0.3/90 groups, respectively. The pre-experimental and experimental periods lasted for 7 and 14 days, respectively. The performance and physiological biochemical indices of dairy cows were determined. The results showed as follows: 1) the milk yield in 0.3/0, 0.2/30, 0.3/30, 0.1/60, 0.2/60, 0.3/60 and 0.1/90 groups was significantly higher than that in the other groups (P<0.05); the milk fat percentage in 0/0 group was extremely significantly lower than that in 0.3/30, 0/60 and 0.3/60 groups (P<0.01), and significantly lower than that in the other groups (P<0.05); the milk total solid in 0.3/60, 0/90 and 0.2/90 groups was significantly lower than that in the other groups (P<0.05); the somatic cell count in milk in 0.3/30, 0.3/60, 0.1/90, 0.2/90 and 0.3/90 groups was significantly lower than that in 0/0, 0.1/0, 0/30 and 0/60 groups (P<0.05). 2) The serum total protein and urea nitrogen concentrations in 0.3/0 and 0.3/30 groups were significantly lower than those in the other groups (P<0.05 or P<0.01); the serum insulin and glucagon concentrations in 0.3/30 and 0.3/60 groups were extremely significantly higher than those in 0/0 group (P<0.01); the thyroxin concentration in 0.3/0, 0/30, 0.3/30, 0/60, 0.1/60, 0.2/60, 0.3/60 and 0/90 groups was extremely significantly lower than that in 0/0 group (P<0.01), and significantly lower than that in the other groups (P<0.05); the triidiothyronin concentration in 0.3/30 and 0.3/60 groups was extremely significantly higher than that in the other groups (P<0.01). 3) The serum glutamic oxalacetic transaminase activity in the groups supplemented with 0 to 0.3 mg Se and 0 to 30 IU kg vitamin E and 0/60 group was significantly lower than that in the other groups (P<0.05); the serum activities of glutamic-pyruvic transaminase in 0.3/60 group and glutathione peroxidase in 0.3/30 and 0.3/60 groups were extremely significantly lower than those in 0/0, 0.1/0, 0/30, 0/60, 0/90 and 0.3/90 groups (P<0.01). In conclusion, the optimal levels of Se and vitamin E are 0.3 mg and 30 to 60 IU/kg, respectively.

The gene-encoded antimicrobial peptides (AMPs) are widely distributed in insects, plants, animals and the human bodies, and served as crucial components in the innate host defenses. In addition to their direct broad-spectrum antimicrobial activities against Gram-positive and Gram-negative bacteria, fungi, some enveloped viruses and parasites, AMPs also show multiple biological activities including antitumor activity, neutralizing endotoxin, anti-inflammatory activity, and chemoattracting memory T cells, monocytes and dendritic cells. AMPs play an important role in the integration of the innate and acquired immune responses, starting the acquired immune system, and enhancing the body against microbial infections. This article has reviewed the multiple biological activities, mechanisms of antimicrobial action and the application prospects of AMPs.［Chinese Journal of Animal Nutrition，2011，23（4）：546 -555］

A　method　for　simultaneous　determination　of　fat-soluble　VA,　VD3　and　VE　in　fish　tissues　by　HPLC　is　presented.　The　sample　preparation　procedure,　which　consist　　of　saponification　and　extraction　by　mineral　ether　was　carried　out.　The　following　chromatographic　conditions　were　used:　VARIAN　Res　Elut　5μC18　90A　column,　mobile　phases　consisted　of　methanol-water　gradient　elution　with　1.0　mL/min　flow　velocity.　All　the　vitamins　were　detected　under　the　wave　length　of　292　nm.　The　linearity　range　between　peak　area　and　vitamin　content　was　0~15　μg/mL　for　VA,　0~10　μg/mL　for　VD3　and　0~20　μg/mL　for　VE.　The　lower　limits　were　0.8×10-3　ng　　for　VA,　0.06×10-3　ng　for　VD3　and　9.0×10-3　ng　for　VE,　respectively.　The　described　analytical　method　is　effective　and　fast,　　which　is　feasible　to　prcess　　a　large　number　of　samples.

With many vital biological functions, lipid is considered to be one of the most important biomolecules in animals. Lipidomics is a novel subject that studies the mechanism of action of lipid metabolic regulation in various vital phenomena. It reveals interactions among lipids and other biomolecules according to a systematic level study on endosomatic lipids. The applications of lipidomics in related subjects are widely reported, such as nutrition and functional genomics. This paper mainly reviews classification and metabolism of lipids, concept, methodology, research status and application advances of lipidomics.

Under some severe pathological conditions induced by serious environment, bacteria or virus, the balance between anti-oxidation and oxidation was disturbed, which leaded to oxidative injury of cells and body, and had negative effects on animal health and production. Vitamin A, C, E and α-lipoic acid were commonly used as antioxidants in animal production. However, a growing body of evidence showed that these oxidants exerted anti-oxidative effects in a relatively low dose, whereas they caused pro-oxidative potential in body when used in a high dose. The pathway involved in the production of reactive oxygen species and the potential mechanism involved in anti/pro-oxidative effect are summarized in this review.

Humans and animals are colonized by multituded of commensal organisms that are essential for growth and development of hosts. Studies on host-bacterial symbiotic relationship could conducive to improve the health status of humans or animals and may contribute to clinical diagnosis and prevention of diseases. In this article we review the Seven aspects detailed in types of symbiotic relationship, postnatal establishment of gut microflora, microbial diversity, adhesion of microbes to gut, bacterial-epithelial crosstalk and their effects on intestinal development anf energy balance, mucosal immunity and disease treatment.［Chinese Journal of Animal Nutrition, 2010，22（3）:519-526］

Yeast cell has a perfect system for protein post-translational modification and secretion. The cell surface display technology based on yeast is a novel eukaryotic protein display technology. It has been successfully used for protein recognition, immobilization and remediation, and becomes an important tool for the study of protein engineering. Yeast cell surface display technology is divided into two systems, which are agglutinin and flocculin, according to the different insertion sites of the yeast cell wall for target heterologous proteins. If introduced to animal nutrition research, this technology will be a promising strategy to reduce the methane production by the regulation on ruminal microbial ecology, which is inducing of production of antibodies for protozoa and methanogen in host; highly active whole cell biocatalysts will be produced by increasing fiber utilization in ruminant and monogastric animal. Therefore, mechanism, characteristic and application of the technology are reviewed in this paper.

Fermented soybean meal by microorganism could decrease anti-nutritional factors, and increase nutrient contents, biological functions. The fermentation effects with different strains were different. This paper reviewed the effects of single strains and multi-strains on fermented soybean meal.

After challenged by intra-and extracellular environmental factors, such as nitric oxide, calcium and pathogenic organisms, the balance between oxidative and antioxidant defense systems in human and animal cells is broken, which results in the accumulation of reactive oxygen species (ROS) within cells, and finally oxidative stress occurs. Oxidative stress can cause DNA damage, such as DNA strand breaks, point mutations, aberrant DNA cross-linking, and mutations in proto-oncogenes and tumor suppressor genes; meanwhile, when challenged by physical or chemical factors, such as depurination and apyrimidinic factors, X-ray, ultraviolet, alkylating agent and intercalator, DNA also could be injured, furthermore, DNA damage is a source to oxidative stress in body. This paper mainly reviewed oxidative stress, DNA damage, and their relationship, which could provide a theoretical basis for a further research.

Metabolomics is an emerging subject following genomics, transcriptomics and proteomics, in which microbial metabolomics is one important branch. From microbial product exploitation to metabolic engineering application, microbial metabolomics has become the focus of research. General research process of the microbial metabolomics was reviewed in this article, including test design, sample collection, data acquisition, data processing and biological interpretation. Besides, this article also introduced the application prospect in development of feed additives and microbial fermentation feed for animals.［Chinese Journal of Animal Nutrition，2011，23（4）：563 -570］

Antimicrobial peptides (AMPs) are a kind of small peptides, which widely exist in nature organisms. They are important parts of the innate immune system of organism. Antimicrobial peptides have a wide range of activities against bacteria, fungi, parasites, viruses, as well as anticancer functions. With the discoveryof more and more antibiotic-resistant microbes, antimicrobial peptides have been applied widely in the field of pharmaceutical industry and food additives. In this paper, the recent research progresses on the sources, the functions, the mechanisms of action as well as the application prospects of antimicrobial peptides were reviewed.

Glutamate is the largest contributor to intestinal energy generation as an essential amino acid for young animal growth, and it is obtained from diets or transformed from glutamine because it cannot be synthesized in vivo. Glutamate is an important substrate for glutathione synthesis and plays a critical role in supplying intestinal antioxidants, and its transporters are responsible for removing glutamate from the extracellular space. Functions and characteristics of glutamate and glutamine transport systems are reviewed in this article.［Chinese Journal of Animal Nutrition, 2011, 23（6）：901 -907］

The aim of this experiment was to investigate the effects of feeding grape seed procyanidins (GSPs) on growth performance, semen quality, testis and epididymis antioxidant indexes of male lambs. A total of forty-eight 4-month-old Dorper (♂)×small Tail Han sheep (♀) F1 male lambs with similarly weight of (22.75±1.2) kg were randomly selected and divided into 4 groups equally. All the lambs fed a basal diet and supplemented with 0 (control group), 10 (10GSPs group), 20 (20GSPs group) and 40 mg/kg BW (40GSPs group) GSPs, respectively. The experiment was conducted over 60 d, with the first 15 d for adaptation and 45 d for test. The results showed as follows:1)average daily gain (ADG) and average daily feed intake (ADFI) in 10GSPs和20GSPs groups were significantly higher than those in the control group and 40GSPs group (P<0.05), with no significant difference between 40GSPs group and control group (P>0.05). No significant difference was observed in feed conversion ratio among GSPs groups (P>0.05). 2) The weight of epididymis in the GSPs groups was significantly higher than that in the control group (P<0.05), and the indexes of testis and epididymis had no significant difference among the four groups (P>0.05). The acrosome integrity in 20GSPs and 40GSPs groups was significantly higher than that in 10GSPs and control groups (P<0.05), and the rate of sperm malformation in 20GSPs and 40GSPs groups was significantly lower than that in control group (P<0.05). 3) The activity of total antioxidant capacity (T-AOC) and glutathion peroxidase (GSH-Px) in testis and epididymis in 20GSPs and 40GSPs groups were significantly higher than those in control group (P<0.05). The superoxide dismutase (SOD) activity in epididymis in three GSPs groups was significantly higher than that in the contol group (P<0.05), and the malonaldehyde (MDA) content in the testis and epididymis in 20GSPs and 40GSPs groups was significantly lower than that in 10GSPs group and control group (P<0.05). 4) In testis, the relative expression levels of SOD mRNA in 20GSPs group and glutathione peroxidase 4 (GPx4) mRNA in 40GSPs group were significantly higher than those in 10GSPs group and control group (P<0.05). There was no significant difference among four groups in the relative expression levels of catalase (CAT) and nuclear factor E2 correlation factor 2 (Nrf2) mRNA (P>0.05). In epididymis, the relative expression levels of SOD mRNA in 20GSPs and 40GSPs groups was significantly higher than that in control group (P<0.05), but had no significantly difference compared with 10GSPs group (P>0.05). The relative expression level of GPx4 mRNA in three GSPs groups was significantly higher than that in control group (P<0.05). Additionally, the relative expression level of Nrf2 mRNA in 20GSPs and 40GSPs groups was significantly higher than that in control group (P<0.05). In summary, dietary supplementation of GSPs can promote the growth and improve the antioxidant status of testis and epididymis of ram, thereby improving semen quality. The optimal GSPs supplemental level is 20 mg/kg BW under the condition of this experiment.

Synthesis and catabolism in animal adipose tissue are mainly regulated by key enzymes of lipid metabolism. Gene expression level determines the amount of enzymes and their activities. This article mainly reviews the progress in effects of gene expression of some key enzymes (fatty acid synthetase, acetylcoenzyme A, hormone-sensitive lipase and lipoproteinesterase) and their activities on lipid metabolism.

Methane emitted from ruminants is a significant contributor to greenhouse gases. Reducing methane emission is of great significance to alleviate global warming and to protect the environment. This paper reviewed measurements, predictive models and nutritional management of methane emission from ruminants to provide a clue for further research on prediction and mitigation of methane emission.［Chinese Journal of Animal Nutrition, 2011, 23（5）：726 -734］

The intestinal tract of animal involves a diversity of microbial environment. Intestinal epithelial cells separate commensal microorganisms and pathogens from the underlying immune cells to be part of the intestinal epithelial barriers. Probiotics are a certain kind of microorganisms that have beneficial effects on the host, and play a part with intestinal epithelial cells and immune cells in constituting three functional barriers which are mechanical barrier, chemical barrier and immune barrier. This article reviewed the intestinal epithelial barrier and micro ecosystem composition, the functions of probiotics in enhancing intestinal epithelial barriers, as well as mechanisms and the interaction between microbe and intestinal epithelium.

This report reviews the adjustment of flavonoids on lipid metabolism,antioxidant of animals and the relation of flavonoids with incretion and immunity and introduces the application of flavonoids in animal production.

This experiment was conducted to evaluate the ileal digestible energy (IDE), metabolic energy (ME) and nitrogen-corrected metabolizable energy (MEn) of soybean oil, lard, phospholipid oil and mixed oil (soybean oil:lard=1:1) for broiler chickens. A total of 576 female Arbor Acres broiler chickens with the body of (640±1) g and at the age of 21 days were randomly divided into one control group and eight trial groups, and each group had eight replicates with eight birds per replicate. Broiler chickens in the control group were fed a basal diet, while those in trial groups were fed new diets. The new diets were prepared using soybean oil, lard, phosphatide oil and blend oil replaced 4% or 8% basal diet, respectively. The ratio of corn to soybean meal in diets of control group and trial groups was the same, which was 12.04:7.00. Titanium dioxide (TiO₂) was used as an indicator added into diets, and the adding level was 0.5%. Excreta was collected on 25, 26 and 27 days of age for measuring the utilization rates of dry matter, nitrogen and energy and calculating the ME and MEn. At the 28 days of age, all birds were slaughtered, and the chyme was collected from the distal ileum for measuring utilization rates of dry matter, nitrogen and energy and calculating the IDE. The results showed that there were extremely significant linear relationships between the soybean oil replacement proportion and the utilization rates of dry matter, nitrogen and energy in chyme from the distal ileum and total intestinal excreta, IDE, ME and MEn (P<0.01); there were extremely significant quadratic relationships between the lard replacement proportion and the utilization rates of dry matte and energy in chyme from the distal ileum and IDE (P<0.01), and there were extremely significant linear and quadratic relationships between the lard replacement proportion and the utilization rates of dry matter, nitrogen and energy in total intestinal excreta and ME, MEn (P<0.01); there were extremely significant linear and quadratic relationships between the phosphatide oil replacement proportion and the utilization rates of dry matter, nitrogen and energy in chyme from the distal ileum and IDE (P<0.01), and there were extremely significant linear relationships between the phosphatide oil replacement proportion and the utilization rates of dry matter, nitrogen and energy in total intestinal excreta and ME, MEn (P<0.01); there were extremely significant linear and quadratic relationships between the blend oil replacement proportion and the utilization rates of dry matter, nitrogen and energy in chyme from the distal ileum and total intestinal excreta, IDE, ME and MEn (P<0.01). Then, according to the proportion of basal diet replacement by correlation between soybean oil, lard, phosphatide oil and blend oil and the energy supplied by soybean oil, lard, phosphatide oil and blend oil in new diets, the regression equations for ME, MEn and IDE of soybean oil, lard, phosphatide oil and blend oil was obtained as follows: ME=0.14_(0.01)+33.66_(1.46) soybean oil replacement proportion+38.82_(1.53) lard replacement proportion+39.90_(1.52) phosphatide oil replacement proportion+50.83_(1.83) blend oil replacement proportion, R²=0.951; MEn=0.10_(0.01)+32.84_(1.27) soybean oil replacement proportion+37.58_(1.44) lard replacement proportion+38.22_(1.43) phosphatide oil replacement proportion+49.75_(1.43) blend oil replacement proportion, R²=0.954; IDE=0.43_(0.02)+41.35_(3.10) soybean oil replacement proportion+41.05_(3.25) lard replacement proportion+41.87_(3.21) phosphatide oil replacement proportion+44.23_(3.22) blend oil replacement proportion, R²=0.811. According to the above regression equation, the IDE, ME and MEn for soybean oil are 41.35, 41.35 and 32.84 MJ/kg DM, respectively; for lard are 41.05, 38.82 and 37.58 MJ/kg DM, respectively; for phosphatide oil are 41.87, 39.90 and 38.22 MJ/kg DM, respectively; and for blend oil are 44.23, 50.83 and 49.75 MJ/kg DM, respectively.

Peroxisome proliferators activated receptor γ (PPARγ) is a kind of nuclear transcription factor which belongs to the nuclear hormone receptor superfamily. It can play important regulatory roles in energy metabolism, cell differentiation, nerve injury, inflammatory reaction, cardiac cerebral and vascular diseases. This paper reviewed the structure feather and biological function of PPARγ and its ligand.

This experiment was conducted to study the effects of mixed acidifier on growth performance, nutrient apparent digestibilities, immune organ and meat quality of weaned rabbits. Three hundred healthy weaned Hyla rabbits with similar body weight and at age of 35 days were randomly divided into 5 groups with 60 rabbits in each group. Rabbits in the control 1 were fed a basal diet, rabbits in the control 2 were fed the basal diet supplemented with antibiotics, and rabbits in the experimental groups were fed the basal diet supplemented with 0.1% (group Ⅰ), 0.2% (group Ⅱ) and 0.3% (group Ⅲ) mixed acidifier, respectively. There were a pretrial period of 5 days followed by an experimental period of 22 days. The experiment results showed as follows:1) dietary different mixed acidifier had no significant difference in final weight, average daily weight gain, average daily feed intake, feed/gain, diarrhea rate and mortality rate (P>0.05), but the average daily weight gain had a trend to increase with the increase of mixed acidifier adding level (P=0.056 4). Compared with control group 1, adding mixed acidifier had a trend to decrease diarrhea rate (P=0.051 8). 2) The apparent digestibilities of energy and neutral detergent fiber in groups Ⅱ and Ⅲ were significantly lower than those in the control group 2 (P<0.05); the apparent digestibility of dry matter in control group 2 was the highest, significantly higher than that in the control group 1 and group Ⅱ (P<0.05), and had no significant difference compared with groups Ⅰ and Ⅲ (P>0.05); the apparent digestibility of acid detergent fiber in groups Ⅱ and Ⅲ was significantly lower than that in the control group 2 and group Ⅰ (P>0.05), and had no significant difference with control group 1 (P>0.05); the apparent digestibility of ash in all experimental groups was significantly higher than that in control group 1 (P<0.01), and had no significant difference with control group 2 (P>0.05); dietary mixed acidifier had no significant influence in the apparent digestibility of crude protein, but had a trend to increase the apparent digestibility of crude protein (P=0.083 3). 3) Adding mixed acidifier had no significant influence in slaughter performance and meat quality (P>0.05). 4) The thymus weight in groups Ⅱ and Ⅲ was significantly lower than that in the control group 2 (P<0.05), and had no significant difference compared with control group 1 (P>0.05); the thymus index in control group 2 was the highest, significantly higher than that in the control group 1 and group Ⅲ (P<0.05), there were no significant differences between groups Ⅰ and Ⅱ and two control groups (P>0.05); compared with the control group 1, dietary mixed acidifier had no significant effect on other immunization indices (P>0.05). Considering all indices of this experiment, the appropriate mixed acidifier supplemental level in the diet of weaned rabbits is 0.3%.

There exists a huge amount of flora with complex structures in the animals' intestine; also, there are many powerful mucosal lymphocytes within the intestinal wall. The intestinal flora plays an important role both in promoting growth and development of the intestinal mucosal immune system and in regulating intestinal mucosal barrier and immune functions. This paper reviews the colonization and characteristics of the intestinal flora, the function of intestinal mucosal immune cells, as well as the regulation of intestinal mucosal barrier and immune functions by the intestinal flora.

This paper reviewed functions and mechanism of action of butyrate in intestinal health maintenance, immunomodulation, neuroprotection, and regulation of gene expression, and briefly introduced its application in animal production to provide references.

Plant essential oil is an aromatic oil-like liquid extracted from plants, which has antibacterial, anti-oxidation and anti-inflammatory functions. Therefore, plant essential oil can be used as a natural antibiotic substitute under the circumstance of antibiotic prohibition in feed. There were many case studies with plant essential oil in monogastric animals, but relatively few studies in beef cattle, whose results suffered wants of uniformity.In this paper, the application and related mechanism of plant essential oil on growth performance, nutrition metabolism, rumen fermentation, methane production and beef quality of beef cattle were reviewed, so as to comprehensively understand the scientific application of plant essential oil in beef cattle production.

In vitro digestion methods for monogastric animal were reviewed accordi ng to simulatation of sites of the digestive tract,sources of digestive enzymes and the ways for separating digested and indigested nutrients in digesta.The adv antages and shortness also were discussed through comparing several in vitro dig estion methods in predicating nutrients digestibility and evaluating feed nutrit ive values.The furture direction for developing in vitro digestion techniques wa s suggested.