In order to characterize the differences in fatty acid composition between varied muscle tissues in Tan sheep and Small Tailed Han sheep,the retention time and concentrations of 31 kinds of fatty acids in biceps femoris,longissimus dorsi muscle and triceps brachii of Tan sheep and Small Tailed Han sheep were determined and statistically compared.The results showed that there was no significant difference in retention time of 31 kinds of fatty acids between varied muscle tissues in both Tan sheep and Small Tailed Han sheep (P>0.05),and the retention time was increased with the elevation of carbon content in fatty acids;compared to the other tested fatty acids,the contents of C16:0,C18:0 and C18:2n6c in varied muscle tissues were all found to be higher in both Tan sheep and Small Tailed Han sheep;extremely significant difference in concentration of C17:0 between varied muscle tissues in Tan sheep and Small Tailed Han sheep was observed (P<0.01).

The aim of the present study was to establish the methods for isolation and identification of mouse hepatocytes with high purity and viability,and to evaluate their purity and biological activity.The mouse hepatocytes were isolated and purified by using two-step in-situ-circulating perfusion method in combination with multi-round of low speed differential centrifugation.Hepatocytes were primarily cultured in adherent culture medium and their viability were evaluated by trypan blue exclusion.PAS reaction and immunofluorescence assay were used to examine their glycogen synthesis ability and CK18 expression level,respectively.The results showed that a total of 1.5×10^6 hepatocytes with >97% of motility rate could be harvested from individual mice in this study.The primary adherence of hepatocytes was observed after 6 h of inoculation under inverted microscope.The adherent cells grew well 72 h post inoculation.The size of the hepatocytes was enlarged with irregular shape,and they were connected with the surrounding cells in island or strip-like junctions.Glycogen deposits in form of purple-red particles were found in hepatocytes in which CK18 was uniformly distributed.PAS reaction in combination with immunofluorescence staining for CK18 demonstrated the high-purity (>90%) of hepatocytes.In conclusion,the mouse hepatocytes isolated by using the established method in this study had high harvest yield and viability,and the cells cultured in adherent culture medium had high purity,providing a foundation for further investigation on metabolism and cytotoxicity of hepatocytes.

In order to analyze the relationship between selenium and immune ability in dairy cows,a total of 50 lactating cows with the similar age,parity and body condition were randomly selected and divided into control group and experimental group according to the serum selenium level.The contents of IL-2,IL-6 and TNF-α in the blood samples of dairy cows were determined by double antibody sandwich method.The results showed that while the serum content of IL-2 of experimental group was lower than control group,no significant difference was observed (P>0.05);there was a positive correlation between serum selenium level and serum content of IL-2 (R=+0.133,P=0.356);while the serum content of IL-6 of experimental group wase higher than control group,no significant difference was observed (P>0.05);there was a significantly negative correlation between serum selenium level and serum content of IL-6 (R=-0.28,P=0.049);the serum content of TNF-α of experimental group was significantly lower than control group (P<0.05);there was a significantly positive correlation between serum selenium level and serum content of TNF-α(R=+0.311,P=0.028).The combined data suggest that the selenium supplementation with appropriate level can improve the immune ability of dairy cows.

[Objective] To study the effect of α- chaconine on proliferation of small intestinal epithelial cells in piglets.[Method] The in vitro cultured porcine small intestinal epithelial cell line (IPEC-J2) was treated with different concentrations of α-chaconine,and the cells were recovered at 24,48,72 h post treatment to determine their proliferation rate by using MTT method,respectively.[Result] After 24 hours of treatment with 0.1 and 0.2 μg/mL of α- chaconine,there was no significant difference in proliferation rate between the two above treatment groups and the control group (P>0.05);the proliferation rate of the 0.4,0.8 and 1.6 μg/mL of α-chaconine treated groups were extremely significantly decreased compared to the control group (P<0.01).After 48 hours of treatment,no significant difference in proliferation rate between 0.1 μg/mL of α-chaconine treated group and the control group was observed (P>0.05);the cells treated with 0.2,0.4,0.8 and 1.6 μg/mL of α-chaconine had extremely significantly lower proliferation rate compared to the control group (P<0.01).After 72 hours of treatment,the proliferation rate of all treatment groups was extremely significantly reduced compared to the control group (P<0.01).[Conclusion]α- chaconine can decrease the proliferation rate of small intestinal epithelial cells,and its inhibitive effect is enhanced with the increase and extension of treatment concentration and duration.

[Objective]To detect the serum level of trace element of copper in experimental dairy cows and to characterize the variation rule of related indexes.[Method]The experimental dairy cows used in this study were selected from a dairy farm in Heilongjiang Province,and were reared under free-choice feeding system with TMR diets.According to the DHI data,50 lactating cows with similar body weight,parity (2-3 times),lactation period (0-10 days),body condition and feeding management were randomly selected.[Result]The correlation between serum copper level and IL-2 content in the experimental dairy cows was R=0.355,P=0.011.There was a significantly positive correlation between serum copper level and IL-2 content in the experimental dairy cows.The serum content of IL-2 in the lactating dairy cows was increased with the elevation of serum copper level.The correlation between serum copper level and IL-1 content in the experimental dairy cows was R=0.215,and the significance was P=0.133,P>0.05.There was no correlation between serum copper level and IL-1 content in the experimental dairy cows.The correlation between serum copper level and TNF- alpha content in the experimental dairy cows was R=0.185,with a significant difference of P=0.198,P>0.05.[Conclusion]There was no correlation between serum copper level and TNF-alpha content in experimental dairy cows.

The purpose of this study was to assess the effects of dietary supplementation of a compound micro-ecological preparation on growth performance,number of fecal microbes,diarrhea rate and serum indexes of calves.A total of 20 calves aged from 3 to 5 months were selected and divided into experimental group (n=10) and control group (n=10) according to their gender and body weight.The calves in the control group were fed with a basal diet,and those in the experimental group fed a basal diet supplemented with a compound micro-ecological preparation containing Saccharomyces cerevisiae,Bacillus subtilis and lactic acid bacteria.The feeding experiment lasted for 30 days.The calves were weighted at the beginning and end of the experiment,and the total weight gain and average daily weight gain during the experiment of the two groups were calculated and statistically compared.The fecal samples of the calves at the beginning and end of the experiment were collected,and the number of fecal microbes of the two groups before and after the experiment were counted and statistically assessed.The diarrhea incidence of the calves in the two separate groups was recorded and compared.At the end of the experiment,the blood samples of the calves were collected,and the main blood indexes of the two groups were determined and compared.The results showed that the dietary supplementation of compound micro-ecological preparation had no significant impact on growth performance of calves (P>0.05);the calves fed the basal diet added with compound micro-ecological preparation had significantly higher number of fecal lactic acid bacteria and significantly lower number of fecal coliform bacteria compared to the control group (P<0.05),with the number of fecal lactic acid bacteria reaching up to 2.28×10^7 CFU/g;the lower diarrhea rate was observed in the calves of experimental group;there were no significant differences in serum biochemical indexes between experimental group and control group (P>0.05).In conclusion,dietary supplementation of compound micro-ecological preparation can effectively improve the intestinal micro-ecology environment and reduce the diarrhea rate of calves.

In an attempt to investigate the impact of dietary supplementation of a Chinese herbal medicine compound additive on activity of ruminal digestive enzymes in sheep,a total of 60 four-month-old healthy Dorper and Small-tailed Han sheep crossbred lambs (F1) of were randomly assigned into the following four groups: the male and female control groups were fed with the basal diet,and the male and female experimental groups fed the basal diet supplemented with Chinese herbal medicine compound additive.The feeding experiment lasted for 45 days.At the end of the experiment,the rumen fluid samples were collected from the lambs,and the activity of protease,carboxymethyl cellulase and alpha-amylase in rumen fluid of the lambs in different groups were determined and statistically analyzed.The results demonstrated that while the dietary supplementation of Chinese herbal medicine compound additive had no significant impact on activity of ruminal protease and alpha-amylase in the crossbred lambs (P>0.05),it significantly elevated the activity of ruminal carboxymethyl cellulase (P<0.05).In addition,the variation of the three tested ruminal digestive enzymes expressed no association with the lambs′ gender.Our results suggest that the dietary supplementation of Chinese herbal medicine compound additive is able to improve the activity of ruminal carboxymethyl cellulase in lambs and thus can promote the digestion and metabolism of forage cellulose in sheep rumen.

Through consulting the relevant published scientific literatures,we found that micro-ecological agents as a green and safe feed additive can improve ruminal and intestinal micro-ecological balance,promote the digestion and utilization of nutrients,improve animal production performance,enhance immunity,and improve the environment of livestock houses.In this paper,we mainly introduced the application of micro-ecological agents in ruminant feed and analyzed its application prospects.

[Objective]To study the effects of compound small peptide preparation on productive performance,morbidity and mortality of broilers,and to provide technical support for its scientific application in broiler production.[Method]A total of 1 200 healthy Ross 308 broilers aged 28 days with the similar weight were randomly divided into four groups,each with four replicates and 75 chickens per replicate.The control group fed a basal diet with no addition of the compound small peptide preparation,and the experimental group 1,2 and 3 fed a basal diet supplemented with 2.0%,2.5% and 3.0% compound small peptide preparation,respectively.[Result]The dietary supplementation of compound small peptide preparation significantly increase the final weight and average daily gain of broilers (P<0.05 or P<0.01),and significantly reduce the feed-weight ratio,diarrhea rate,and morbidity and mortality associated with respiratory diseases (P<0.05 or P<0.01).[Conclusion]The compound small peptide preparation can significantly improve the productive performance and health status of broilers,and the recommended dietary supplementation level is 2.5%-3.0%.

The intestine is not only the digestive and absorbing organ of nutrients but also the largest immune organ.Weaning stress can cause serious damage to the intestinal tract of piglets,which always results in atrophied intestinal villi,decreased feed intake,disordered digestion and absorption of nutrients,and reduced immunity,thus causing a series of symptoms such as diarrhea,indigestion and slow growth in piglets.Therefore,improving intestinal function and repairing intestinal injury by nutritional regulation ways can protect intestinal health of piglets,improve survival rate and productive performance,and increase breeding benefits.In this paper,the nutritional regulation technology of piglets intestinal health and its application were reviewed.

In this study,the effect of feeding of corn straw silage prepared with Panjiang No.7 and air-dried corn stalk on weight gain of fattening sheep under fully confined rearing condition was evaluated and compared.The results showed that under the same feeding and management condition,the average daily gain of individual sheep fed corn straw silage prepared with Panjiang No.7 was 213.44 g,which was 62.66 g higher than that fed air-dried corn stalk (150.78 g).During the feeding experiment,the average economic benefit for individual sheep fed corn straw silage prepared with Panjiang No.7 was 228.38 Yuan,which was increased by 73.62% compared to that fed air-dried corn stalk (131.54 Yuan),indicating an obvious improvement of feeding economic benefit.

Microbial fermented feed is a new type of environment-friendly feed developed rapidly in recent years.It has the functions of improving the feed utilization rate,enhancing the health level of livestock and poultry,improving the quality of animal products and ameliorating the breeding environment.This paper mainly reviews the application of microbial fermented feed in the production of pigs,cattle and aquatic animals,in hoping to provide references for related researches.

The reduction of cultivated land and environmental pollution have led to a shortage of feed raw materials.The food wastes have the advantages of extensive source,low price and numerous varieties,and have been widely used as a raw material for animal feed.This paper reviews the research and application of food wastes at home and abroad,in hoping to provide references for animal husbandry practitioners to alleviate the shortage and insufficient supply of feed raw materials.

Bacillus coagulans has the dual biological functions of lactic acid bacteria and Bacillus.Due to its good resistance to gastric acid,bile salt,high temperature and long-term storage,the Bacillus coagulans arouses widespread concern.In this paper,the biological function of Bacillus coagulans and its application in livestock and poultry production were reviewed,in hoping to provide references for the research and scientific application of Bacillus coagulans in livestock and poultry production.

Defensin is cationic,endogenous and cysteine enriched antimicrobial peptide which is widely distributed in animals,plants and insects.It plays an important role in animal immune regulation and plant defense.This paper reviews the concept,type,structure and action mechanism of defensin,summarizes the research progress of in vivo tissue expression and in vitro expression of defensin in cattle,horse,sheep,pig,deer and camel,and prospects the future applications of defensin in biopharmaceutical industry and livestock feed production.

The Brachyury gene is a transcription factor encoded by the T-box gene family,which has been found in many animals including coelenterates.It plays an important role in regulating embryonic development,cell migration and other aspects of the organism.Its function also involves certain physiological processes such as organ formation during embryonic development.It has been found that Brachyury gene is directly associated with human tumor diseases,the development of chordal cord and the abnormal growth of tail type in animals.In this paper,the research progress of involvement of Brachyury gene in tumor disease and formation of short tail traits in animals was reviewed.

The objectives of this study were to understand the best growth state of Eutamias sibiricus,and to provide guidance for their artificial reproduction.From April to May during 2010 to 2016,the growth and development of wild young Eutamias sibiricus reared in artificial nest box in Zuojia Nature Reserve of Jilin Province was observed and characterized,and were compared with those reared in fully artificial feeding conditions.The results showed that the correlation coefficient (r) between body weight and body length was 0.946 7,the correlation coefficient (r) between body weight and tail length was 0.921 0,and the correlation coefficient (r) between body length and tail length was 0.985 0.Compared to their counterparts reared in fully artificial feeding conditions,the young Eutamias sibiricus reared in wild artificial nest box had shorter duration of growth and development as well as higher correlation coefficients,body weight and body length.

In order to assess the effect of fertilization on yield and quality of Pennisetum purpureum Schum cv.Guiminyin,the variations of agronomic traits,yield and nutritional quality of Pennisetum purpureum Schum cv.Guiminyin under different fertilization levels were characterized using orthogonal design experiment with three factors and three levels.The results showed that good comprehensive production performance was obtained via optimization of the nitrogen,phosphorus and potassium ratio of fertilizer.The fertilizer combination of N20P10K20 had the best fertilization effect.With the fertilization ratio of N 20 kg/667 m^2,P 10 kg/667 m^2 and K 20 kg/667 m^2,the annual fresh grass yield of Pennisetum purpureum Schum cv.Guiminyin reached up to 11 267.5 kg/667 m^2,and the converted hay yield was 2 520.7 kg/667 m2,which were increased by 39.74% and 46.30% compared to the CK (without fertilization treatment),respectively.The crude protein content was 12.68% and was increased by 25.60% compared with the CK.

In order to screen the silage maize varieties suitable for planting and popularization in Daqing area of Heilongjiang Province,a total of 15 silage maize varieties were introduced and compared in yield and agronomic traits.The differences in fresh weight,dry weight,plant height,stem diameter,leaf number,green leaf number and ear height between the introduced silage maize varieties were characterized,and the correlation between yield and agronomic traits was analyzed.The results showed that the varieties of Zhongyuandan No.32 and Beiyu silage No.1 had the best comprehensive performance,and both of their yield exceeded 63 000 kg/hm^2.In addition,there was a extremely significantly positive correlation between ear height and yield.This study provides a reference for the cultivation and promotion of silage maize in Daqing area.

The amount of the sheep stocks and mutton production in Inner Mongolia accounts for 1/3 of the total number of China,ranking the first place in China over years.Two-thirds of them come from indoor farming systems.In order to provide references for study and promotion of welfare feeding technology of stall-fed sheep in Inner Mongolia and establishment of a welfare breeding mode of stall-fed sheep suitable for Inner Mongolia,we evaluated the current situation of welfare of stall-fed sheep in agricultural area of Inner Mongolia.It will be beneficial for realizing the sheep welfare breeding in Inner Mongolia,breaking down the barriers of international trade in animal welfare,and enhancing the international image and market competitiveness of Inner Mongolia sheep industry.

Milk urea nitrogen (MUN) as a biological index of protein nutritional status and protein utilization efficiency of dairy cows has been widely recognized by researchers at home and abroad.In this paper,the definition,detection methods,production mechanism and nutritional and non-nutritional factors affecting urea nitrogen in milk were summarized,in hoping to provide reference for dairy cow breeding.

With the development of economy and the division of labor in society,the demand for professional and technical talents is becoming more and more urgent.Applied education is the inevitable trend of higher education development in agricultural and forestry colleges in the future.Animal production,as a highly practical course,should grasp its characteristics in the specific teaching process,improve students′ understanding efficiency of theoretical knowledge,strengthen practical application,and enhance the competitiveness of social survival for the purpose of training innovative professionals in line with the future developmental needs of animal husbandry industry.

Genetic evaluation,as the core content of Livestock Breeding,is a highly theoretical part of the teaching process,which needs to be combined with practice to help undergraduates understand its content.At present,there are a lot of software applied in livestock genetic evaluation.Compared with the other software,WOMBAT software has the advantages of simple parameter setting and fast running speed.Taking the cashmere yield and weaning weight of goats as examples,we established a single trait and multi-trait (no) repeatability model,and used this software to estimate the genetic parameters of the above traits effectively,which can be used in classroom teaching to help undergraduates understand the application of genetic evaluation in livestock breeding.

The veterinary medicine major is a discipline with strong practicality and thus improving the undergraduates′ practical ability is of great significance to promote the employment of college students and cultivate applied talents in veterinary medicine.This paper objectively analyzed the problems existing in the practical teaching of veterinary medicine specialty,and discussed the reforming measures of the practical teaching mode of veterinary medicine specialty,in hoping to providing references for the reform of practical teaching of veterinary medicine specialty in colleges and universities.

Animal science major has strong practicality,so carrying out efficient and stable professional practical training can help undergraduates consolidate professional knowledge in animal science,improve professional skills and accumulate practical experience.Based on the accumulation and analysis of the practical experience of animal science specialty in Inner Mongolia University for Nationalities,the optimization and diversification of the practical mode between classes,the centralized and decentralized mode of graduation practice,and the open experimental mode of scientific research,innovative training and innovative experiment were discussed to a certain extent,in hoping to provide references for the establishment of practical mode of animal science specialty in local ethnic colleges and universities.

Veterinary Immunology is a basic course of animal husbandry and veterinary medicine specialty.Due to the abstract and profound theoretical concepts,there is great pressure in teaching of this course.In order to enable students to master immunology knowledge,stimulate their learning interests and improve their comprehensive quality,the teaching content,methods and means of this course were reformed and explored in combination with the personnel training program of applied universities and the characteristics of Veterinary Immunology,in hoping to improving the teaching quality of this course.

In order to implement the early diagnosis and timely intervention of pododermatitis and mastitis of dairy cows in dairy farms,a total of 681 dairy cows selected from a dairy farm in Daqing of Heilongjiang Province were subjected to pododermatitis diagnosis by using a newly developed HD camera-based device,and the diagnostic speed and results were compared with the traditional plane mirror reflection method.In addition,a total of 100 dairy cows randomly chosen from the above herd and were subjected to mammary duct terminal scoring by using the new type device,and the relevance and consistency of the diagnostic results between the HD camera-based method and LMT diagnostic method were statistically analyzed in combination with the DHI data of the dairy farm.The results showed that the newly developed device had the advantages of fast image transmission speed,good imaging effect,long standby time,fast and accurate diagnosis,low cost and good convenience in discriminative diagnosis of pododermatitis and rapid diagnosis of mastitis in dairy cows.It could accurately determine the different stages of pododermatitis,and could greatly improve the efficiency and reduce labor intensity during the diagnosis process of pododermatitis and mastitis compared with the traditional diagnostic methods.Furthermore,there was a strong correlation and a good consistency in the mammary duct terminal scoring results between HD camera-based method and LMT diagnostic method.Our results provide a new method for early diagnosis and prevention of pododermatitis and mastitis in dairy farms.

African swine fever outbreaks have occurred in China since 2018 and it spread rapidly in a short period of time,posing a certain threat to the healthy development of China′s pig industry and the smooth operation of the national economy.We conducted a risk assessment on comprehensive prevention and control of epidemic diseases in scaled pig farms in Taicang of Jiangsu Province,and put forward some corresponding prevention and control countermeasures such as improving epidemic prevention and control system,enhancing special rectification of livestock and poultry breeding and strengthening supervision of live pigs′ transporting vehicles,in hoping to provide references for improving the comprehensive prevention and control level against the epidemic diseases in scaled pig farms in this region.

Ehrlichia canis is an important zoonotic infectious pathogen and causes monocytic ehrlichiasis in canine.In order to diagnose a case of pet dog clinically characterized by fever,depression and paleness of mucosa,the blood routine test,blood biochemical test,real-time fluorescent quantitative PCR,and Ehrlichia canis antibody test were carried out.This case was confirmly diagnosed as Ehrlichia canis infection.The doxycycline hydrochloride was used to treat the dog and good curative effect was obtained.