With the development of breeding industry, the odor emission of largescale breeding farms has attracted wider attention. This article summarizes the regulation of odor emission in the process of livestock and poultry breeding and the treatment and utilization of breeding wastes, analyzes the influencing factors of odor emission in livestock and poultry farms, and puts forward suggestions for the development of the breeding industry in the future. It provides a theoretical basis for reducing gas emissions.

In this study, through transcriptome analysis of different tissues of sheep, a collection of specific long noncoding RNAs of muscle, skin, and adipose tissue was obtained, and based on Pearson's coefficient, the proteincoding genes in the 10 kb/100 kb region of the upstream and downstream were predicted. The lncRNAmRNA regulatory network was established, and the AnimalQTLdb database was used to screen long noncoding RNAs that may have important economic traits. The results showed that a total of 36,340 lncRNAs were predicted. Tissuespecific analysis was performed on them based on the τ index. 213 musclespecific lncRNAs, 467 skin tissuespecific lncRNAs, and 295 fatspecific lncRNAs were identified. The upstream and downstream genes of these three tissuespecific lncRNAs may be involved in the regulation of muscle growth, epidermal development, fat synthesis and other biological processes. Two important expression modules were discovered through the constructed IncRNAmRNA interaction network, which are related to keratinization and fat synthesis, respectively. QTL analysis showed that there are 14 lncRNAs that may serve as candidate long noncoding RNAs for sheep muscle and fatrelated traits. The research results provide reference for the application of in sheep breeding.

This study aimed to explore the expression of EEF1D gene on wool follicle growth cycle and wool quality of sheep. Ten visceral tissues of Chinese Merino（Xinjiang Junken type)(fine wool sheep) were collected, three wool and skin tissues of Chinese Merino and Prolific Suffolk sheep (course wool sheep) which were in the process of hair follicle development were collected. The wool fiber diameter of the two breeds at three stages of wool follicle development was measured by microscope, and the expression level of EEF1D gene in 10 tissues and skin tissues at different wool follicle development stages was detected by real-time quantitative PCR. Results showed that the fiber diameter of Chinese Merino was extremely  lower than that of Prolific Suffolk sheep at three stages of wool follicle development (P＜0.01). The expression abundance of EEF1D gene in skin tissues of Chinese Merino (Xinjiang Junken type) was significantly higher than that in other nine tissues (P＜0.05). In anagen and catagen phases, the expression level of EEF1D gene in the fine wool sheep was significantly higher than that of coarse wool sheep (P<0.05). The high level expression of EEF1D gene, therefore, induces telogen of hair follicle.

To study the effect of different dosages of compound microecological agents on reproductive performance of sows and growth performance of piglets, 50 sows were randomly divided into 5 groups (control group, group Ⅰ, group Ⅱ, group Ⅲ and group Ⅳ) which were added with 0 mg/kg, 100 mg/kg, 200 mg/kg, 400 mg/kg and 800 mg/kg compound probiotics in the basal diet, respectively. The results showed that compared with control group, the total milk production, lactose rate and weaning litter weight for group Ⅰwere significantly increased (P<0.05), and the dorsal and Lumbar thickness loss was significantly decreased (P<0.05). In group Ⅱ, group Ⅲ and group Ⅳ, the average daily feed intake, total milk production, milk fat rate, lactose rate, number of weaned live piglets, weaning litter weight, weaning weight, average daily gain and survival rate were significantly increased (P<0.05) compared with control group, and the dorsal and lumbar thickness loss was significantly decreased (P<0.05). Compared with group Ⅱ, the total milk yield, milk fat rate, lactose rate, weaning litter weight, weaning weight, average daily gain were significantly increased(P<0.05) in group Ⅲ and group Ⅳ. The results showed that adding compound microecological preparation to the basic diet of sows can improve reproductive performance, milk composition of sows, and growth performance of piglets, and 400 mg/kg is the optimal dosage for clinical application.

This experiment aimed to investigate the effects of plant essential oil and organic acids on broiler growth performance, intestinal morphological structure, serum biochemical indicators and the potency of the Newcastle disease (ND) antibody. A total of 1 008 one dayold healthy Cobb broilers with similar weight were randomly assigned to 3 groups, with 6 replicates per group and 56 birds per replicate for a 42day trial (the ratio of male to female is consistent in each replicate). The control group was fed cornsoybean meal, antibiotic group added 20 mg/kg of virginiamycin to the base diet, the experimental group added 100 mg/kg compound plant essential oil and 900 mg/kg compound organic acids to the basic diet. The results showed:(1) at 1~42 days of age, the ratio of feed to gain (F/G) of the experimental group was significantly lower than that in the control and antibiotic group (P<0.01), and the average daily feed intake (ADFI) was significantly lower than that in the antibiotic group (P<0.05). (2) Compared with the control group, at 42 days of age, the duodenal villi height of the experimental group was significantly higher (P<0.05), and the ratio of villi height to crypt height (V/C) was extremely higher(P<0.01). The jejunal villi height of the experimental group was significantly higher in all stages (P<0.05). At 42 days of age, the crypt depth extremely was significantly lower (P<0.01), and the V/C was significantly higher (P<0.01). The ileum villi height and V/C of the experimental group was extremely higher in all stages (P<0.01), and the crypt depth was extremely lower at 14 and 42 days of age (P<0.01). (3) The content of alanine aminotransferase (ALT) of experimental group was significantly lower than that in the control and antibiotic group at 42 days of age (P<0.05), the content of lactate dehydrogenase (LDH) was significantly lower than that in the control group at 28 and 42 days of age (P<0.05), the content of alkaline phosphatase (ALP) was significantly higher than that in the control group in all stages (P<0.05). (4) At 28 days of age, the titer of ND antibody of the experimental group was extremely higher than that in the control group (P<0.01), and significantly higher than that in the antibiotic group (P<0.05). The titer of ND antibody of the experimental and antibiotic group was significantly higher than that in the control group at 42 days of age (P<0.05). Thus, the addition of 100 mg/kg of compound plant essential oil and 900 mg/kg of compound organic acid mixture in the diet have positive effects on growth performance, intestinal morphological structure, serum biochemical index and ND antibody titer of broilers, and has the potential to become an antibiotic substitute.

The experiment was conducted to explore the effects of cyclic intermittent lighting on performance, egg quality and blood indexes of Roman laying hens aged from 21 to 28 weeks. 270 Roman laying hens were randomly divided into three treatments, the control group (C) adopted the illumination program of “16L:8D”, the experimental group 1(T1) the illumination program of “16h［3hL/1hD］: 8D” and the experimental group 2(T2) the illumination program of “16h［45minL/15minD］: 8D”. The production performance and egg quality of laying hens were measured during the experiment. The results showed that there was no significant difference in feed intake, laying rate, feedegg ratio, and egg quality among the three groups aged from 21 to 28 weeks（P>0.05）. However, the daily feed intake of T1 and T2 was significantly lower than that in group C by 3.13% and 2.48% aged from 25 to 28 weeks, respectively (P<0.05). The serum triglyceride content in T2 was significantly lower than that in group C and T1 by 22.18% and 15.18%, respectively (P<0.05). The results showed that compared with the “16L:8D” lighting program, “16h［45minL/15minD］: 8D” cyclic intermittent lighting program has no significant effect on the daily feed intake, laying rate, feedegg ratio and egg quality of laying hens aged from 21 to 28 weeks, but it can reduce the daily feed intake of laying hens aged from 25 to 28 weeks, and significantly reduce the serum triglyceride content.

The residue of two heavy metals (Cu and Zn) was investigated in feces of different physiological stages of sheep. The standardized sheep farms (18 farms in total) in 5 cities in Hebei province were selected and fresh feces samples (46 in total) were collected in different physiological stages of sheep. The content of two metals were measured by atomic absorption spectrometry. The results showed that there was some difference among different physiological stages in Cu or Zn content.As for Zn content, no difference (P>0.05) was found among all stages of sheep feces, however, Zn content in feces was the highest in adult sheep including ram and ewe, with an average of 68.32 mg/kg. The Zn content in other stages of sheep feces reached 63.26 mg/kg in suckling lamb, 62.17 mg/kg in fattening sheep, and 60.98 mg/kg in bred sheep; for Cu content，the content in feces of growing sheep was the highest among all stages of sheep, with 41.88 mg/kg in growing sheep, however, compared with other stages of sheep, the Cu content demonstrated no difference (P>0.05) among all feces. The Cu content in fattening sheep feces, lamb and adult sheep feces were 39.36, 38.5, and 37.17 mg/kg, respectively. From the correlation between two metals, there was a linear negative correlation (P<0.01, r=-0.84) between the Cu and Zn content in sheep feces, and the regression equation was y=-1.0069x+100.62. In this study, both Zn and Cu contents in feces of all physiological stages of sheep did not exceed the native standard, however, the environmental risks from heavy metals in feces should be given  enough attention.

The reproductive capacity of livestock and poultry is the key factor to improve the productivity of animal husbandry, of which the germ cell is the main carrier. The genesis, development and maturation of germ cells are regulated by signaling pathways. Among them, PI3K/Akt signaling pathway plays an important role in cell proliferation, differentiation and apoptosis. Recent studies showed that the activation of PI3K/Akt signaling pathway plays an important role in the process of spermatogenesis and follicular development. This review summarizes the regulatory role of PI3K/Akt signaling pathway in livestock and poultry reproduction, in order to provide a new perspective for improving livestock and poultry reproductive capacity from the molecular mechanism.

The livestock welfare science started from the early 1960s, when various problems emerged in the intensive production mode of livestock. It aims to improve the production process and to make production more reasonable, so that many problems might be reduced and the overall productivity could be promoted. In recent years, livestock welfare curriculum has become more and more significant due to the improvement of people's awareness of animal welfare. In the first half year of 2020, classes were all suspended because of the COVID19 pandemic, as a result, colleges and universities all over the country began to launch online teaching. Livestock Welfare Course, as one of the popular elective courses of animal science in agricultural colleges and universities, initiated its online teaching activities for the first time. Taking the online teaching of Livestock Welfare during the pandemic, this paper introduces the implementation of Livestock Welfare in detail, and summarizes the effect of online teaching under the background of epidemic situation. At the same time, in view of the difficulties and problems encountered in online teaching, this paper puts forward five pieces of enlightenment of online teaching, so as to further improve the teaching quality, as well as to provide reference for the construction of online teaching for similar courses in agricultural colleges.

China is a major producer of edible fungi with extremely rich resources in spent mushroom substrate (SMS). This paper reviews the nutritional value of SMS, the influence of feeding SMS on ruminant foraging behavior, production performance, blood biochemical indexes, rumen tissue morphology, organ index, gastrointestinal microflora and related gene expression, in order to provide a reference for the development and utilization of SMS fodder.

The objective of this experiment was to study the relationship between miR-1-3p and its target genes and secondary hair follicles development in Qianhua mutton   merino sheep. Bioinformatics was used to predict the target genes of miR-1-3p; fluorescence quantitative PCR was adopted to detect the relative expression levels of miR-1-3p and its target genes;Western blot was used to determine the protein quantification of Fibroblast Growth Factor 14 (FGF₁₄) protein of miR-1-3p target gene; Dual luciferase reporter gene assay was used to verify the targeting relationship between miR-1-3p and candidate target genes.FGF₁₄ was identified as the candidate target gene of miR-1-3p by Targetscan v7.0, miRanda and RNA22 software. MiR-1-3p was of low expression in anagen and high expression in telogen. On the contrary, the relative expression of FGF₁₄ mRNA was high in anagen and low in telogen, which was consistent with the expression pattern of FGF₁₄ protein. The results of the double luciferase reporter gene assay showed that the target gene of miR-1-3p was FGF₁₄. In conlusion, there is a targeted regulatory relationship between miR-1-3p and FGF₁₄ in secondary hair follicles of Qianhua mutton merino sheep, and miR-1-3p may regulate secondary hair follicles development in Qianhua mutton merino sheep by negatively regulating FGF₁₄.

The purpose of this study was to investigate the effects of coconut oil on rumen epithelial development of goat lambs. Twenty-four Hainan black goat lambs aged 10 days were used and randomly divided into 4 groups with 6 replicates in each group for a period of 90 days experiment. The basal diet was supplemented with 0 (Ctrl group), 4 g/d (group LCO), 6 g/d (group MCO) and 8 g/d (group HCO) coconut oil, respectively. The rumen weight and volume were measured after slaughter, and the paraffin sections were prepared. The development of the rumen epithelium was detected under light microscope. The results showed that the rumen volume of lambs in MCO group was significantly higher than that in the other three groups (P<0.05). There were no significant differences in rumen weight and rumen index. The superficial area of ruminal epithelial papilla in LCO and MCO groups significantly increased (P<0.05), and the density of epithelial papilla in HCO group significantly decreased compared with other groups (P<0.001). The length and thickness of rumen papilla in HCO group had no significant effects (P>0.05). Coconut oil significantly increased stratum basale (SB), stratum granulosum (SG) in LCO and HCO groups (P<0.05), and stratum spinosum (SS) in MCO and HCO groups (P<0.05). The results suggest that 6 g/d of coconut oil could significantly increase the volume of rumen, stimulate the differentiation of epithelial papilla cell, and promote the development of rumen in lambs.

The purpose of this experiment was to study the effects of extract and fermentation of Eucommia ulmoides leaf on development of chicken bone. 2-day-old chickens weighing about 40 g were randomly divided into three groups (n=10 for every group): control group, Eucommia ulmoides leaf extract group and Eucommia ulmoides leaf fermentation group. The chickens were fed for 60 days. At the end of the feeding period, the tibia was dissected, detected by CT, cut and stained. Morphological and structural changes were observed under the microscope, and bone morphometric parameters were measured with CT image analysis software. The results showed that the CT values of bone (P<0.05), trabecular area (P<0.05) in Eucommia ulmoides extract group and Eucommia ulmoides leaf fermentation group were significantly higher than those in the control group (P<0.05) while trabecular separation was lower (P<0.05). Detected by inductively coupled plasma mass spectrometry, the contents of magnesium, calcium and zinc in tibia of the two experimental groups were significantly higher than those in the control group (P<0.05). Significant difference in copper was found in tibia in Eucommia ulmoides leaf fermentation group (P<0.05). The above results indicate that the addition of Eucommia ulmoides leaf extract and Eucommia ulmoides leaves fermentation to the chicken diet could improve the bone development and bone metabolism, increase the content of trace elements in the chicken bone, increase the bone remodeling activity, and improve the health status of the chicken to a certain extent.

To investigate the dynamic succession process of the rumen fungal community in Tibetan sheep from birth to adulthood under grazing conditions, rumen fluid from 27 Tibetan sheep was collected for internal transcribed spacer（ITS） gene sequencing at nine time points (0, 2, 7, 14, 28, 42, 56, 70, and 360 days (D) of age; n=3). The results showed that the succession of ruminal fungi was related to age and diet during adulthood, and the dominant fungi at the phylum level included Ascomycota, Neocallimastigomycota, and Basidiomycota (>75% total relative abundance). At the phylum level, the abundance of Ascomycota and Neocallimastigomycota varied greatly with increased age. From D0-D360, the relative abundance of Ascomycota was reduced from 75.4% to 10% and the relative abundance of Neocallimastigomycota was increased from 0.5% to 86.1%. At the genus level, the fungal communities were age-related. The dominant genera at D2 were Saccharomycopsis and Cladosporium, and the dominant genus at D70 was Neocallimastix. This study indicated that the succession process of rumen fungi was greatly affected by feeding conditions and the age of sheep, and the presence of fungi was detected in the undeveloped rumen on the first day after birth. This study provides a new perspective for studying the colonization process of rumen fungi in grazing lambs and may help to develop new management strategies promoting target fungal colonization that may improve the rumen function of the host.

In order to study the effects of the same grazing conditions on blood biochemical indices, antioxidant capacity and immune function of different beef cattle, 20 adult Simmental, Mongolian and Charolais cattle with similar body weight and body condition were randomly selected as experimental cattle in West Ujumchin Steppe，Xilingol League and Inner Mongolia. Blood samples were taken in the morning of the last day of the experiment period. Serum hormones, antioxidant indexes, serum immunoglobulin and interleukin content were measured by ELISA. The results showed as follows: (1) the contents of IgA, IgG and IgM in serum of Simmental and Mongolian cattle were significantly higher than those of Charole cattle under the same grazing and feeding conditions (P<0.05). (2) Mongolian cattle have better antioxidant capacity than the other two kinds of beef cattle. The serum MDA content of Mongolian cattle was significantly lower than that of the other two breeds (P<0.05), the serum SOD activity of Simtal and Mongolian cattle was significantly higher than that of Charolai cattle (P<0.05), and the serum CAT activity of Mongolian cattle was significantly higher than that of Charolai cattle (P<0.05). (3) The metabolism of Mongolian cattle was stable under grazing condition. The contents of HDL-C and ALB in serum of Mongolian cattle were higher than those of Simmental and Charole cattle, but the content of LDL-C was lower (P<0.05).In conclusion, there are differences of the same grazing condifions in blood biochemical indexes, antioxidant indexes and immune function indexes among different beef breeds, and Mongolian cattle have better adaptability and stress resistance, which could provide reference for breeding of local beef breeds.

The objective of this study was to investigate the effects of high temperature in summer on physio-biochemical indexes and behavior of Xianan cattle, and the anti-heat stress effect of shading. In this experiment, a 2×2 two-factor design was used, 16 healthy Xianan cattle with similar weight (289.63±17.32)kg were selected. Experiments were carried out in summer and autumn, and were divided into two groups: shading treatment and non-shading treatment (n=8) for each season. The results indicated as follows：(1)the average THI in summer group was 76.87, the THI reduced to 75.10 by setting up the shading, the average THI in autumn group was 61.63 and the average THI of shading group in autumn was 61.10.（2）Compared with summer group, the rectal temperature and respiratory rate of Xianan cattle of shading group in summer decreased significantly (P<0.05). (3)Compared with summer group, the serum Heat shock proteins 70 (HSP70), Heat shock proteins 90 (HSP90), Cortisol (COR) contents of Xianan cattle in the two autumn groups were significantly decreased (P < 0.05), and the contents of Super Oxide Dismutase (SOD), Total antioxidant capacity (T-AOC), Triiodothyronine (T3), Thyroxine (T4) significantly increased (P>0.05).（4）Compared with summer group, the water drinking frequency decreased significantly in shading group in summer (P<0.05), and walking time and lying time decreased (P>0.05). Compared with summer group, the lying time and feeding time of the two autumn groups increased significantly (P<0.05), and the water drinking frequency and feeding time decreased significantly (P<0.05). (5) Through the correlation analysis of various indexes, it was found that respiratory rate, rectal temperature and heat shock protein expression levels were negatively correlated with antioxidant indexes, and there was a certain correlation with behavior. To sum up, under the condition of high temperature in summer, the behavior of Xianan cattle changes, its respiratory rate speeds up and the rectal temperature, COR and HSPs content in plasma increase, while the antioxidant ability decreases, this indicates that heat stress reaction may occur in Xianan cattle. After setting up the shading net, the respiratory rate and rectal temperature of the Xianan cattle are effectively reduced, the cortisol content and heat shock protein content in the plasma are reduced, and the antioxidant capacity is enhanced, which means that the shading treatment can relieve the heat stress of Xianan cattle to a certain extent.

The use of ultrasonography to diagnose early pregnancy in dogs has certain limited advantages. Researches on gestational sac development and changes in uterine blood flow were especially few. Eighteen early pregnant Beagles were monitored by application of B-mode ultrasound and Doppler. The outer (OLL) and inner (ILL) latero-lateral diameters, and the outer (ODV) and inner (IDV) dorso-ventral diameters of gestational sac were measured. The peak systolic velocity (PSV), end-diastolic velocity (EDV), pulsatility index (PI) and resistance index (RI) of uterine artery were measured. The analysis on the correlation between the gestational sac development and gestation age, and the changes of uterine blood flow was also conducted. The results showed OLL in day 24 to 25 was significantly higher than in day 23, day 26 to 27 higher than in day 24 to 25,and was remarkably lower than in day 28(P<0.05). ILL in day 23 of preganancy was significantly higher than in day 20 to 21, and day 26 to 28 remarkably higher than day 23 to 24 (P<0.05). ODV was significantly higher in day 23 than day 20, day 25 higher than day 23 and remarkably lower than day 28(P<0.05). IDV was higher in day 22 than in day 20, day 25 higher than day 22, day 27 higher than day 25 and lower than day 28(P<0.05), and there was no significant change in uterine arterial blood flow on days 22, 25, 28. Ultrasound exploration technology has successfully monitored the rapid growth of OLL, ILL, ODV and IDV of the gestational sac in the early trimester of Beagle dogs with the rapid growth of gestational days, and the gestation time has a positive effect on them. Uterine arterial blood flow does not change significantly during the measurement period. The results indicate good pregnancy and normal fetal development.

In order to further explore the dynamic effects of new feed additive zinc oxide nanoparticles (ZnO NPs) residues on the process of hydrolysis and acidification of livestock and poultry manure and related mechanisms, this study took cattle manure with different concentrations of ZnO NPs as the research object, used 16S rRNA high-throughput sequencing to characterize the changes of functional microbial community during hydrolysis and acidification processes in anaerobic digestion of cattle manure, and combined the profiles of hydrolysis and acidification products and cumulative methane production to reveal the influence and mechanism of ZnO NPs on these processes. Results showed that in the presence of 5, 10, and 30 mg/g TS of ZnO NPs, the content of dissolved organic matter in the anaerobic digestion system increased significantly (P<0.05), and the content of volatile fatty acids accumulated in a large amount in the group with ZnO NPs of 5 mg/g TS, which was significantly higher than those in other groups (P<0.05). Besides, significant differences in the community of different functional bacterial genera to the concentration of ZnO NPs (P<0.05) were obtained. Also, ZnO NPs at 5 mg/g TS was found to be more conducive to the growth of functional bacterial genera involved in hydrolytic acidification, such as Herbinix, Caproiciproducens, Tepidanaerobacter, Clostridium_sensu_stricto_7, and Ureibacillus. While high concentrations of ZnO NPs (30 and 100 mg/g TS) severely inhibited the enrichment and expression of hydrolytic and acidifying functional genera, and the higher the ZnO NPs concentration, the stronger inhibition existed. Therefore, it can be seen that ZnO NPs with higher concentrations can adversely affect the hydrolysis and acidification of cattle manure by reducing the relative abundance of hydrolytic acidification functional bacteria, thus, in practice, the residue of ZnO NPs in livestock and poultry manure should be avoided as much as possible.

Horizontal drum aerobic composting adopts horizontal drum as an aerobic reactor, which can realize the full mixing reaction of materials, oxygen and microorganisms through the rotation of the drum and thus humify the material. Windrow composting is to pile up the materials into long and narrow strip piles under aerobic conditions, and use mechanical or manual ventilation regularly. In order to verify the difference between horizontal drum aerobic composting and windrow aerobic composting, the biogas residue after dry anaerobic treatment was used as the main raw material, and corn straw and chicken manure after crushing were used as auxiliary materials. Results showed that at 13th day of the experiment, the temperature of horizontal drum aerobic composting no longer rose, the Germination Index (GI) was 1.02, the carbon nitrogen raotio was 14.36, the HA/FA was 1.26, and the composting product was thoroughly decomposed, the duration of composting was far less than 29 days for windrow composting. The total nutrients of horizontal drum compost products increased by 0.94%, humic acid content was 24.85 g/kg, cellulose degradation rate was 33.45%, hemicellulose degradation rate was 34.33%, lignin degradation rate was 15.33%, the total nutrients of windrow compost products increased by 0.65%, humic acid content was 22.08 g/kg, cellulose degradation rate was 29.33%, hemicellulose degradation rate was 30.26%, lignin degradation rate was 10.28%. The above indicators of the products of horizontal drum composting are significantly higher than those of windrow composting products of strip stacking (P＜0.05), revealing its superiority. In conclusion, compared with the windrow composting, horizontal drum aerobic composting can accelerate the composting process, reduce the composting time, improve the composting efficiency and ensure the composting quality.

This experiment was conducted to study the effect of light color on rabbit immune performance under high temperature environment. 150 Iran rabbits weaned at 35 days were randomly divided into 5 treatment groups, with 3 replicates in each treatment group, and 10 in each replicate. The control group was irradiated with white light and the temperature was controlled at 24°C; the test group was irradiated with white light, red light, green light and blue light, and the temperature was controlled at 30 ℃. The illumination intensity was set to 100 lx, and the illumination time was 14 h∶10 h (L∶D), and the experimental period was 30 d. The results showed that compared with the control group, the weight and index of spleen and thymus, splenic nodule diameter, splenic artery lymphatic sheath area, thymic cortex thickness and IL-2 content were significantly reduced in the white light group compared with the control group (P<0.05). Area ratio of thymic cortical medulla had a decreasing trend (P>0.05), while the content of TNF-α and IL-1β increased significantly(P<0.05). Compared with the white light group, the immune organ weight and index, spleen nodule diameter, splenic lymphatic sheath area, thymic cortex thickness, and IL-2 content in the green light group and blue light group increased significantly (P<0.05). Area ratio of thymic cortical medulla had an upward trend (P>0.05), while the content of TNF-α and IL-1β decreased significantly (P<0.05). In summary, green light and blue light can effectively alleviate the immunosuppressive effect of high temperature environment on rabbits, promote the development of rabbit immune organs, and improve immune performance.

In order to construct porcine circovirus type 1 (PCV1) and porcine circovirus type 3 (PCV3) chimeric viruses PCV1-3, and to lay the foundation for the development of PCV3 vaccine, this study constructed a chimeric porcine circovirus (PCV1-3) DNA clone by replacing the ORF2 gene of PCV1 with the ORF2 gene of PCV3 using the PCV1 genome as the skeleton. PCR and sequencing results showed that the infected clone of pCv1-3 was successfully constructed. The infected clone was transfected into PK-15 cells, and the 4th generation virus was detected by immunoperoxidase monolay assay (IPMA) and Western Blot, and the recombinant virus PCV1-3 was successfully rescued. The titer of the fourth-generation virus was measured and the titer was 10_5.13 TCID₅₀/mL. A new chimeric virus PCV1-3 was successfully rescued and it laid a foundation for further research on PCV3 vaccine.

In order to understand the pathogen infection of dead adult Muscovy ducks in a farm in Zhoukou City, Henan Province, this study intendesd to identify the pathogens in Muscovy ducks submitted for inspection through necropsy observation, bacterial isolation and culture, Gram stain microscopy, and 16S rRNA sequence analysis. The isolated bacteria were tested for pathogenicity, drug susceptibility and 6 kinds of drug resistance genes. The results showed that (1) most of the affected ducks showed myocardial hemorrhage, enlarged liver, yellow-white fibrinous exudate covered by the adventitia, and peritonitis at autopsy. (2) The liver was aseptically collected and inoculated on fresh blood agar plates and SS plates. The results showed that after inoculation and culture, the blood agar plates grew as hemolytic positive cocci with smooth surfaces, and the SS plates grew as colorless and transparent negative bacilli with a black center in the middle. The results of 16S rRNA amplification and sequencing, nucleotide homology analysis and sequence genetic evolution analysis showed that the two strains were more than 99% homologous with Enterococcus faecalis and Salmonella, respectively. (3) Pathogenicity test results showed that both strains were pathogenic, and mixed infection increased the mortality of mice by 50%. (4) Drug susceptibility test showed that the isolated Salmonella and Enterococcus faecalis were completely resistant to doxycycline, and Salmonella was completely resistant to gentamicin. In addition, the two isolates showed different degrees of resistance to the remaining 9 antibiotics. (5) The results of drug resistance gene analysis showed that Salmonella detected tetracycline Tet O, Tet S resistance genes and aminoglycoside ant(3")-Ia resistance genes, and Enterococcus faecalis detected tetracycline Tet L resistance genes. In conclusion, in this study, the pathogenic bacteria Salmonella and Enterococcus faecalis were isolated from the tissue of a diseased Muscovy duck at a duck farm in Zhoukou City. Drug susceptibility test and drug resistance gene analysis confirmed that the two strains had a certain degree of drug resistance. It provides a certain theoretical basis for the control of the disease in clinical practice.

The intractable diarrhea was found in fattening pigs about 80 days old on a pig farm, with complex shapes of feces. In order to identify the pathogen, the samples of diseased pigs were collected. Viral DNA was extracted, and virus detection was performed by RT-PCR method. Pathological changes and histopathological changes were observed and analyzed. The real-time fluorescence quantification results showed that PCV-2 was strongly positive. The autopsy found that there was a slight infarction in spleen and an atrophy in the lymph nodes. The histological observation revealed that the intestinal mucosal epithelial cells of the ileum were significantly proliferated, changing from a single layer to multiple layers. The number of lymphocytes in the lymph nodes and spleen was significantly reduced. This study showed that PCV-2 was the main pathogen causing diarrhea in fattening pigs.

Antibiotic Resistance Genes (ARGs) are a kind of newly emerged pollutants, which can make microorganisms show resistance to one or more antibiotics. They have existed in nature before antibiotics are used for medicine. In recent decades, the wide use of antibiotics in aquaculture has promoted the horizontal transfer and wide spread of ARGs. A large part of antibiotics ingested by animals can not be absorbed, and are excreted into the environment through urine and feces, resulting in pollution. ARGs can also enter the human body through the food chain and directly endanger human health. This paper summarizes the generation, types, discovery methods and drug resistance mechanism of ARGs, and systematically summarizes the elimination strategies of ARGs according to the research results at home and abroad in recent years, so as to provide reference for dealing with ARGs under the background of feed prohibition of antibiotics in livestock breeding. 

Skeletal muscle is the most abundant and highly specialized tissue in the body, accounting for about 40% of the body weight. Most skeletal muscle is composed of a mixture of muscle fibers with different contractile, metabolic, fatigue resistance, and pathophysiological vulnerabilities. Since the number of muscle fibers in animals has been basically constant after birth, the growth and development of muscle fibers mainly depends on the increase of muscle fiber volume and the transformation of types, and the transformation results will lead to the change in the proportion of the main muscle fiber types in the muscle, and directly affect the meat quality characteristics such as meat color, intramuscular fat deposition, and tenderness, and finally lead to differences in muscle quality. Therefore, this paper summarizes the classification and characteristics of muscle fibers, as well as the factors and mechanisms affecting the transformation of muscle fiber types, in order to provide reference for the classification of skeletal muscle fibers and the exploration of their transformation, and provide a new theoretical basis for the improvement of livestock meat quality.

In order to investigate the polymorphism sites of PFN1 (Profilin-1) gene and the expression patterns of its mRNA in pig skeletal muscle tissues, the experiment chose Tibet pigs (TP) and Yorkshire pigs (YP) as experimental animals and performed single nucleotide polymorphism (SNP) screening and genotyping in the CDS and 5'UTR regions of PFN1 gene by Sanger sequencing technology, so as to predict and analyze the functional characteristics of transcription factors before and after SNPs mutation of PFN1 gene. RT-qPCR was adopted to detect the mRNA expression levels of PFN1 gene in the leg muscle and longissimus dorsi muscle of TP and YP at 30-day, 90-day,180-day old respectively. The results showed that there existed three SNPs in the promoter regions of PFN1 gene and the gene frequency between TP and YP was significantly different. Moreover, eight new transcription factor binding sites were generated, which were closely related to the regulation of processes including the growth of skeletal muscle and the morphogenesis and maintenance of cell. PFN1 gene achieved the highest expression level at 30 days old and had an overall downward trend with the age, and its expression quantity in the TP at 90 and 180 days old was significantly (P<0.05) or extremely (P<0.01) lower than that of YP. In summary, the polymorphism of SNPs sites of PFN1 gene in pigs are associated with the differential expression of mRNA in skeletal muscle, which suggests that PFN1 gene may play a critical role in the early development of skeletal muscle in pigs as well as in the maintenance of muscle fibers, and these findings lay the foundation for the further exploration on its molecular mechanisms.

To investigate the biological characteristics of Bone morphogentic protein 7 (BMP7) and its regulation on reproductive physiology of female yaks, primers were designed based on yak BMP7 gene (NW_005392954.1), the cDNA of ovary and uterus of yak in estrus were used as templates for amplification, and the bioinformatics analysis of amplification products was carried out with the help of DNAMAN 8.0 and NCBI websites in this study. Western blot and qRT-PCR were used to quantitatively analyze BMP7 protein and mRNA in ovary and uterus of yaks. The results showed that the amplified BMP7 gene was 428 bp, encoding 142 amino acids. The gene sequence of BMP7 was 98.59% homologous to that of buffalo, cow, goat and other ruminants, and there were signal peptides at positions 0-29 of amino acids, which belonged to secreted protein. The western blot and qRT-PCR results showed that the ovarian expression was significantly higher than that in uterus during estrus (P<0.05). The results of this study suggest that BMP7 may be involved in the regulation of reproductive performance of yaks, and provide reference for the research of reproductive physiological mechanism of yaks under high pressure and low oxygen environment.

This study was conducted to investigate the effects of adding 2000IU/kg  25-hydroxycholecalciferol (25-OH-D₃) on growth performance, bone development and gene expressions of nuclear vitamin D receptor (nVDR), membrane vitamin D receptor (mVDR), and type IIb phosphate transporter in the duodenum of Ross 308 broilers from 1 to 14 days of age. A total of 140 Ross 308 broilers were randomly divided into 2 treatments with 5 replicates per treatment and 14 broilers per replicate. Two levels of 25-OH-D₃ (0 and 2 000 IU/kg) were added to the basal diet (without supplementing vitamin D). Broilers were given access to mash feed and water ad libitum during the experiment. The test lasted for 14 days. Results showed that the addition that of 2 000 IU/kg 25-OH-D₃ significantly increased the body weight gain and feed intake of broilers from 1 to 14 days of age, and it decreased the feed conversion ratio of broilers (P<0.05). The addition of 2000 IU/kg 25-OH-D₃ increased the weight, length, ash weight, ash content, calcium content, and phosphorus content of tibia in broilers from 1 to 14 days of age(P<0.05). 25-OH-D₃ did not affect tibia diameter of broilers (P>0.05). Compared with the basal diet, the addition of 2 000 IU/kg 25-OH-D₃ significantly increased the mRNA expression levels of nVDR, mVDR and NaPi-IIb in the duodenum of broilers (P<0.05).These data indicated that the addition of 25-OH-D₃ can increase the mRNA expression levels of nVDR, mVDR and NaPi-IIb in the duodenum, promote the absorption of phosphorus in the small intestine, and improve growth performance and bone development of broilers.

The purpose of this experiment was to explore the effects of vegetable tannin on growth performance, slaughter performance and meat quality of Qinchuan beef cattle. 24 healthy Qinchuan beef cattle weighing （240±20） kg were randomly divided into 6 groups with 4 replicates in each group. The control group was fed basic diet, and the experimental groups were fed basic diet with 3.22, 6.44, 9.66 and 12.88 g/kg DM vegetable tannin, respectively, which were divided into Experimental group I, II, III and IV. The analysis of total weight gain in the whole period showed that of the experimental group Ⅲ was significantly higher than the control group (P<0.05). The total weight gain of group IV was 5.00%, 5.29%, 8.25% and 16.53% higher than that of group II, IV, I and control group, respectively. The average daily gain of each experimental group was significantly higher than that of the control group (P<0.05). At the end of the experiment, the abdominal circumference index of group IV was significantly lower than that of other groups (P<0.05). According to slaughter test, the carcass weight, net meat weight, slaughter rate and other indicators of group III with the best fattening effect were significantly higher than those of the control group (P<0.05). Although the feed consumption of group III was high in the whole period and so was the feed cost per cattle per day, the weight gain of group III was the largest in the whole period of fattening. According to the estimation of real-time market price of live beef cattle, the breeding benefit of this group was the largest. It is concluded that adding different amounts of vegetable tannin to the diet of Qinchuan beef cattle can improve some growth performance indexes of Qinchuan beef cattle, including slaughter rate, net meat rate, tenderness and color of beef, and can effectively improve the breeding efficiency.

The purpose of this experiment was to analyze the differences of volatile organic compounds in the muscles of three black bone chicken breeds based on gas chromatography-ion mobility spectroscopy (GC-IMS), which will provide scientific and theoretical basis for the evaluation of black bone chicken breed resources and the cultivation of new black bone chicken breeds with good meat flavor. The same part of pectoralis major muscle in Yugan black bone chicken, Zhusi black bone chicken and Silky black bone chicken was taken for GC-IMS determination of volatile organic compounds. The results showed 66 kinds of volatile organic compounds were determined through GC-IMS method, among which 47 kinds of substances have been  identified, mainly being aldehydes, alcohols, ketones, esters and other organic compounds. The slower growing local breeds (Yugan black bone chicken，Silky) had higher levels of 13 volatile organic compounds than that of the faster growing chicken (Zhusi chicken) (P<0.05), including (E)-2-octenal, Heptanal, (E)-2-pentenal, Pentana, (E)-2-Heptenal, (E)-2-Heptenal, Benzaldehyde, hexanal, Ethanol, 1-Octen-3-ol, 1-Pentanol, 1-Heptanol, 2-Heptanone. The characteristic volatile organic compounds of Yugan black bone chicken were benzaldehyde, 2-propanol and 3-pentanone. That of Zhusi chicken were 3-methylbutanal, 1-butanol, ethyl acetate, ethyl 2-hydroxypropanoate. The known determined organics were analysed by PCA, which revealed three categories. Both GC-IMS top view and fingerprints can directly and fast tell the differences and characteristics of volatile organic compounds among three black bone chicken breeds and individuals. Silky and Yugan black bone chickens with slower growth rate contained more aroma substances such as aldehydes alcohols, ketones, etc. In the process of cultivating new black-bone chicken breeds, Silky and Yugan black bone chicken breeds with slower growth rate can be introduced for hybrid breeding, so as to cultivate new black-bone chicken breeds with better meat flavor.

This study was conducted to investigate the effects of dietary supplementation of yeast culture (YC) on growth performance and apparent digestibility of Hu sheep. Sixty male Hu sheep (20.70±2.82 kg initial body weight) with similar age were randomly assigned to four treatments for a 70-day feeding experiment, which were CON group, 0.5% YC group, 1% YC group, 2% YC group. Each group had 15 repetition,each repetion 1 sheep. The results showed that the apparent digestibility of neutral detergent fibre (NDF) and acid detergent fibre (ADF) in Hu sheep fed 1% to 2%YC diet was significantly higher than the CON group (P<0.05). With the increase of YC, there was a tendency that the final weight (FBW,P=0.151) and dry matter intake (DMI,P=0.836) increased, and the feed-to-weight ratio (F/G,P=0.110) of Hu sheep reduced. Overall, these results clarified the dietary supplementation of 2% YC can improve production performance and fiber digestion of Hu sheep.

The sources of stench in livestock and poultry farms are diverse and complex. In recent years, with the increase in scale and intensification of the breeding industry, the problem of odor pollution generated during the breeding process has attracted widespread attention, and the prevention and control of odor becomes urgent. Emission reduction at the source is one of the effective measures to reduce odor emissions. Therefore, this study uses meta-analysis to evaluate the mitigation potential of NH₃ and H₂S by seven types of feed additives. The results found that prebiotics and natural extracts have best emission reduction effects. The emission reduction rates for NH₃ are 17.17% and 17.01%, respectively, and the emission reduction rates for H₂S are 15.82% and 14.29%, respectively. The results provide a reference for selecting suitable feed additives to reduce odor emission from the source. 

In order to understand the variation law of winter environmental indicators and the health status of sucking calves in the newborn calf barn of Angus beef cattle breeding farm in southern Xinjiang, the newborn calf barn in January of an Angus breeding farm in southern Xinjiang was selected as the monitoring object, and the temperature, humidity, noise, carbon dioxide (CO₂), ammonia (NH₃), hydrogen sulfide (H₂S), methane (CH₄), total suspended particles (TSP), inhalable particulate matter (PM₁₀) and other environmental indicators in the winter calf house were monitored. The physiological and biochemical indexes of lactating calves were measured, and the correlation between environmental indicators and their physiological and biochemical indexes was analyzed and evaluated. The results showed that the average winter temperature of calf houses (-7.0±4.02 ℃) was seriously lower than the limit value (5~35 ℃) of the China industry standard (CIS) Environmental Quality Standard for Livestock and Poultry Farms (NY/T 388-1999). NH₃ and H₂S gases were not detected. Humidity, noise, CO₂, NH₃, H₂S, CH₄, TSP, PM₁₀ were all within the CIS range. The daily cycle change of environmental parameters showed that the temperature only conformed to the CIS limit at 15:00-18:00, and it was seriously lower than the CIS limit in about 21 h. The humidity from 00:00-09:00 was  above the CIS limit (80%)about 9 h. The CO₂ concentration exceeded the CIS limit (3 000 mg/m³) at 15:00 and 21:00. The correlation analysis showed that temperature was negatively correlated with respiratory rate and major diseases (fever, cough, pneumonia, loss of appetite, eye disease) in lactating calves (P<0.01). PM₁₀ was positively correlated with respiratory rate, eye disease, cough and wheezing, pneumonia, and loss of appetite (P<0.01). Humidity and TSP were positively correlated with fever, cough and asthma, pneumonia, loss of appetite and eye disease (P<0.01). CH₄, noise was positively correlated with fever, cough, asthma, pneumonia and loss of appetite (P<0.01). CO₂ was positively correlated with cough and wheezing (P<0.01). The results of this experiment show that the change of low temperature and high humidity in the winter environment of newborn calf houses in Angus beef cattle breeding farms in southern Xinjiang is the main factor affecting the health of newborn calves.