In order to improve the yield of antifungal substances produced by Lactobacillus paracasei （L. paracasei） N22 obtained previously, the response surface method was used to optimize the culture conditions for antifungal substances produced by L. paracasei N22, with Pichia pastoris as the yeast indicator and the size of inhibition zone as the evaluation index. The carbon source and nitrogen source in the MRS culture medium were optimized, and the effects of different levels of culture temperature, initial pH value and fermentation time on yield of antifungal substances produced by L. paracasei N22 were assessed. The results showed that the culture temperature, initial pH value and fermentation time were the main determinative factors. The optimal culture conditions for antifungal substances produced by L. paracasei N22 were determined by using Box-Behnken experiment design and response surface method the culture temperature was 34.16 ℃, the initial pH value was 5.33, and the culture duration was 35.44 h. Under these conditions, the largest diameter of inhibition zone was 16.34 mm, and the desirable rate was 97.90%. After verification, the largest diameter of inhibition zone was 16.58 mm. The culture conditions determined in this study increase the yield of antifungal substances produced by lactic acid bacteria.

This paper introduces the bacterial biofilm and its formation process, describes the conception of bacterial quorum sensing （QS） system, and expounds four types of regulative mechanism of QS system, including the AHL-LuxI/LuxR based QS system in Gram-negative bacteria, the QS system in Gram-positive bacteria, the LuxS/AI-2 mediated interspecific QS system, and the AI-3/ epinephrine/norepinephrine signaling system. The roles of QS system in bacteria and its regulative mechanism in formation of bacterial biofilm are elaborated, in hoping to provide references for the development of lactic acid bacteria agents and the investigations on antimicrobial resistance of pathogenic bacteria.

In order to reveal the molecular mechanism underlining the resistant feature of Haloxylon ammodendron, the gene of transcription factor HabHLH74 was cloned from Haloxylon ammodendron and was subsequently expressed in Escherichia coli （E. coli） by using molecular biology technology in this study. The results showed that ① The cDNA sequence of complete coding region of HabHLH74 was successfully amplified using RT-PCR assay, and the length of the coding sequence was 1 218 bp. According to the coding sequence, the physical and chemical properties of its encoding protein were predicted. ② A prokaryotic expression vector of pET28a （+） -HabHLH74 was constructed, and the HabHLH74 protein was expressed successfully in E. coli. The molecular weight of the obtained protein was 43.6 kDa. ③The induced expression condition was optimized by a single factor test. The optimal IPTG concentration, induction temperature and induction time were 0.5 mmol/L, 37 ℃ and 6 h, respectively. ④ Under the optimized induced expression condition, the HabHLH74 protein was expressed in inclusion bodies in E. coli. After decreasing the induction temperature （at 16 ℃ or 25 ℃）, the target protein was still expressed in inclusion form in E. coli.

When developing the compound microbial additives for improving the quality and nutrition of silage, the antagonistic patterns between the different microbes should be given priority for obtaining the best combining effect. In this study, the regular agar plug diffusion method and cup-plate method were applied separately for fungous and bacterial antagonism detection with 1/2 combination, and only the weak antagonism between Candida utilis and Aspergillus niger was observed. Except for the above result, the antagonisms between Bacillus subtilis and Candida utilis, Trichoderma viride and Aspergillus niger were also detected by using full combination spotting method. The antagonism was also identified with microscope observation of the contact region between Trichoderma viride and Aspergillus niger. The antagonistic detection results of the 6 species of microbes indicated that lactic acid bacteria were easy to combine with other tested microbes as no significant antagonism. Candida utilis was antagonistic with Bacillus subtilis and Aspergillus niger, therefore, it could combine with lactic acid bacteria and Trichoderma viride. Bacillus subtilis or Aspergillus niger could individually combine with lactic acid bacteria. In conclusion, compared with 1/2 combination-based agar plug diffusion method and cup-plate method, full combination spotting method has the advantages of convenient operation, complete interaction, uneasy contamination, and comprehensive information.

The aim of this study was to assess the effects of concentrated feed supplementation in the perinatal period on weight gain, blood physiological and biochemical indices, lactation performance of grazing Mongolian ewes grazed in the Gobi areas and growth performance of their lambs. A total of 20 gestational Mongolian ewes averagely weighted （60±5.54） kg with similar physical condition were selected and randomly assigned into an experimental group （n=10） and a control group （n=10）. The basal diet of the control group was supplemented with 300 g corn per ewe per day, and that of the experimental group was supplemented with 300 g self-prepared concentrated feed per ewe per day. The supplementary feeding experiment had a pre-feeding period of 5 days and a formal feeding period of 60 days. All the tested ewes were weighted at the initial and final stage of the supplementary feeding experiment, and the total weight gain was calculated; at the end of the supplementary feeding experiment, the ewes were sampled for determination of blood routine indices and serum biochemical indices; from 15^th to 85^th day after lambing, the milk yield of the ewes was determined every 10 days by using weight difference method; the birth weight and 90-day-old weight of the lambs were measured, and the daily weight gain of the lambs within the 90 days of age was calculated. The differences in the above indicators between experimental group and control group were statistically assessed.The results showed that during the supplementary feeding experiment, no significant （P>0.05） difference in the total weight gain between experimental group and control group was observed, the weight loss of the ewes in experimental group was 1.71% lower than that of the ewes in control group; there were no significant （P>0.05） differences in blood routine indices and serum biochemical indices between experimental group and control group; during the entire lactation period, the ewes in experimental group had higher milk yield compared to those in control group, and significant （P<0.05 or P<0.01） difference was observed at the 75^th and 85^th day after delivery; compared with the lambs in control group, the 90-day-old weight and the daily weight gain within the 90 days of age of the lambs in experimental group were increased （P>0.05）. In summary, the supplemental feeding with concentrated feed in the perinatal period can increase the milk yield of postpartum grazing Mongolian ewes and improve the daily weight gain of lambs.

The brewer′s spent grain （BSG） has nutritional characteristics such as abundant protein and phenolic compounds, low energy, and high fiber. In livestock and poultry production, BSG has good performance in improving reproductive ability, promoting the balance of intestinal microbial population, reducing feed cost, and increasing net income. Dietary replacement of a certain proportion of concentrated feed with BSG is recommended under the premise of fully considering the production stage and purpose of livestock and poultry.

The aims of this study were to explore a new technique of corn straw modulation and to improve the diet utilization rate. A feeding experiment was carried out in beef cattle using the diets based on corn straw fermented with compound enzyme preparation （experimental groupⅠ） and live yeast preparation (experimental groupⅡ). The basial diet was served as control. The effects of feeding different diets on production performance and breeding benefits of beef cattle was assessed. The results demonstrated that the experimental groupⅡhad significantly （P<0.05） higher average daily weight gain compared to the experimental group Ⅰand control group, and the feed cost of per kilogram weight gain of the experimental groupⅡwas 0.91 yuan and 1.83 yuan lower than that of the experimental group Ⅰand control group, respectively. In summary, feeding the diets based on corn straw fermented with live yeast preparation significantly improves the production performance of beef cattle, and increase the feeding benefits.

The CRISPR/Cas9 is a new type of RNA-targeted gene editing system. In recent years, the CRISPR/Cas9 gene editing technology has gained rapid development. Due to its economical, efficient and convenient features, CRISPR/Cas9 gene editing technology is widely used in breeding, medicine, industry and other fields. This paper introduces two types of newly developed gene editing technologies, elaborates the structure and function of CRISPR/Cas9, expounds the principle of CRISPR/Cas9 gene editing technology, and summarizes the application of this technology in forage grass, in hoping to provide references for investigating the forage grass gene function and improving forage grass traits by applying CRISPR/Cas9 gene editing technology.

A method for determination of enrofloxacin and ciprofloxacin residues in chicken eggs was developed using high-performance liquid chromatography coupled with tandem mass spectrometry （HPLC-MS/MS）. After extraction by 1% acetic acid in acetonitrile and purified by hexane, the samples were analyzed by the established HPLC-MS/MS method. The calibration curves of enrofloxacin and ciprofloxacin were linear in the range of 0.5-500 ng/mL （r ≥ 0.999）; the recoveries of enrofloxacin in chicken eggs ranged from 87.7% to 99.1%, and those of ciprofloxacin in the samples ranged from 89.1% to 101.4%; the limit of detection and the limit of quantification of the established HPLC-MS/MS method for enrofloxacin and ciprofloxacin were 0.5 μg/kg and 1.0 μg/kg, respectively. The residues and elimination regularity of enrofloxacin and its metabolite ciprofloxacin in chicken eggs were preliminarily revealed by using a HPLC-MS/MS based method the enrofloxacin and its metabolite were accumulated rapidly in eggs after the chicken were administrated, the metabolism of trace enrofloxacin was slow after 8 days of drug discontinuation, and the metabolism of enrofloxacin was complete after 25 days of drug discontinuation.

In this paper, the status of contamination associated with pathogenic microorganisms in raw milk of dairy cows with mastitis is introduced, the prevalence of antimicrobial resistant pathogenic microorganisms causing dairy cows mastitis is expounded, and the corresponding control measures on pathogenic microorganisms associated contamination in raw dairy milk are proposed. Many species of pathogenic microorganisms such as Escherichia coli, Staphylococcus aureus, Streptococcus spp. and Klebsiella spp. are observed in raw milk of dairy cows with mastitis. The presence of pathogenic microorganisms in mastitis milk samples are varied in different regions, and the pattern of antimicrobial resistance as well as the distribution of antimicrobial resistant determinants of the mastitis associated pathogenic microorganisms are also different. This review provides a reference for reducing drug residues and drug resistance due to abuse of antibiotics, controlling the contamination associated with pathogenic microorganisms in raw milk of dairy cows with mastitis, and improving the prudent and rational use of antibiotics.

This study was conducted to evaluate and compare the mutton quality of Gobi sheep and Qahar sheep raised under natural grazing conditions. The slaughter performance as well as the physical indicators and nutritional components of the triceps brachii, longissimus dorsi and biceps femoris of the 12-month-old Gobi sheep and Qahar sheep were determined and statistically compared. The results showed that Qahar sheep had significantly （P<0.05） higher live weight and carcass weight compared to Gobi sheep, while Gobi sheep had significantly （P<0.05） higher slaughter rate; higher L^* and a^* values were observed in Qahar sheep meat, the cooked meat rate of Qahar sheep ranged from 39.59% to 45.94%, and Qahar sheep meat had better performance in color and luster as well as water retention property; Gobi sheep meat was tender and soft, with the shear force of 7.16-8.47 N; the protein content of Gobi sheep meat and Qahar sheep meat were 17.63%-19.54% and 17.18%-18.77%, respectively, and the total amino acids content were 70.73%-75.98% and 67.29%-70.86%, respectively. In conclusion, the meat nutritional value of Gobi sheep is slightly better than that of Qahar sheep.

In this study, a total of 208 individuals of Wuliangshan black-bone chicken were chosen to screen the mutations of c.A99G locus in exonⅠdigested by Hsp92Ⅱand the mutations of c.C565G locus in exonⅡdigested by MvaⅠin the adiponectin gene （accession number NC_006096） via polymerase chain reaction-restriction fragment length polymorphism （PCR-RFLP）. There were three genotypes （AA, AB and BB） in c.A99G locus and three genotypes （CC, CD and DD） in c.C565G locus. Analysis of the population genetic characteristics showed that the information content of the peptides at the c.A99G locus was at moderate-polymorphic level, while that of the peptides at the c.C565G locus was at low-polymorphic level. The Chi-square （χ²） fitness test demonstrated that both loci of c.A99G and c.C565G of the population were in equilibrium state.

In this paper, the preparation methods, immunomodulatory functions and applications of placenta extracts in life and production are introduced. The placenta extracts have immunomodulatory, anti-oxidative, anti-neoplastic and nutritional functions. The preparation methods of placenta extracts mainly include ultra-filtration method, enzymatic hydrolysis method and microbial fermentation method. Each method has its advantages and disadvantages. Accordingly, when choosing the preparation method of placenta extracts, comprehensive consideration should be taken according to the own conditions and requirements as well as previous experience. In the aspect of skin care, placenta extracts can be added as an antioxidant component to skin care products to delay skin aging. In terms of disease treatment, placenta extracts can improve the clinical symptoms and liver function of patients with hepatitis, have a negative regulatory effect on the proliferation of pancreatic cancer cells, show a certain therapeutic effect on hypersensitivity, and exhibit a significant effect in nerve regeneration. Placenta extracts have broad application prospects in research and development of health care products, skin care products as well as in disease treatment.

[Objective] To assess the effect of extracts from Epimedium brevicornu on growth performance of red claw crayfish （Cherax quadricarinatus）, and to evaluate the clinical safety of the extracts on target animal red claw crayfish.[Method] A total of 150 healthy red claw crayfishes were randomly assigned into 5 groups control group, recommended dose group, 3 times recommended dose group, 5 times recommended dose group, and 10 times recommended dose group. The basal diet of the 4 treatment groups was supplemented with 0.1%, 0.3%, 0.5%, and 1.0% extracts from Epimedium brevicornu, respectively. There were three parallel treatments for each group and 10 red claw crayfishes in each parallel treatment. The experimental red claw crayfishes were fed in separate boxes. After a 7-day-long administration of the extracts by mixed feeding method, the clinical symptoms, morphological parameters, blood physiological and biochemical indicators, and hepatopancreatic index were observed and measured. [Result] Compared to the control group, the extracts from Epimedium brevicornu had no significant （P>0.05） effects on weight gain rate, specific growth rate and condition factor of the red claw crayfish within the range of 10 times clinical recommended dose; the recommended dose and 3 times recommended dose of the extracts extremely significantly （P<0.01） elevated the total hemocyte counts and the serum TP level, and extremely significantly （P<0.01） reduced the ALT activity; the recommended dose of the extracts significantly （P<0.05） decreased the large-granule cell ratio. There were no significant （P>0.05） differences in serum TG, BUN and T-CHO levels and hepatopancreatic index between the treatment groups and the control group, and the histological structure of the hepatopancreas of the red claw crayfish in the treatment groups was normal. [Conclusion] Feeding the diet supplemented with extracts from Epimedium brevicornu within 3 times recommended dose for consecutive 7 days was safe for red claw crayfish.

The grazing sheep in pastoral areas of Inner Mongolia are raised in the natural grassland. They are renowned for fresh, delicious, juicy, taint-free, and pollution-free meat in China and abroad. In the face of the increasingly enhanced ′animal welfare′ trade barriers from the developed countries, it is urgent to create a brand of welfare mutton sheep in Inner Mongolia, to break world trade barriers, and to improve the international competitiveness of the mutton sheep industry in Inner Mongolia. In this paper, the welfare status of grazing sheep in pastoral areas of Inner Mongolia is analyzed and evaluated, in hoping to provide references for accelerating the welfare process of grazing sheep in pastoral areas of Inner Mongolia.

In order to promote the research and development of Brucella Rev.1 vaccine and related vaccines, the nucleic acid of the Brucella Rev.1 vaccine strain was extracted, and the genome-wide sequencing for Brucella Rev.1 vaccine strain was carried out and analyzed through PacBio platform. The results showed that the full-length genome of the Brucella Rev.1 vaccine strain was 3 299 187 bp, and the G+C content was 57.2%; two circular genomes of chromosome 1 and chromosome 2 were assembled; the size of chromosome 1 and chromosome 2 was 2 121 370 bp and 1 177 817 bp, respectively, and the G+C content of chromosome 1 and chromosome 2 was 57.2% and 57.3%, respectively. The sequences of Ery, BLS and VirB10 genes of the Brucella Rev.1 vaccine strain were bioinformatically compared and analyzed with their counterparts of 9 Brucella reference strains, and the sequence similarity among those genes were observed, ranging from 97.4% to 100%.

In this study, a highly virulent orf virus （ORFV） strain was isolated from the clinical samples of the diseased sheep. After 90 consecutive passages on goat fibroblasts, the obtained ORFV clinical strain was attenuated. The genomes of the highly virulent ORFV strain and the attenuated ORFV strain were extracted and designated as ORFV-QD and ORFV-RD, respectively. A total of 3 sets of specific primers were designed based on the whole genome sequence of ORFV published on GenBank and used to amplify the gene fragments of B2L, F1L and VIR in ORFV-QD and ORFV-RD. The obtained genomic fragments were cloned into pMD-19T vector and were subsequently transformed into DH5α competent cells. After identification, the positive recombinant plasmids were sequenced. The obtained target gene sequences were aligned, and the nucleotide sequence homology within the same gene between ORFV-QD and ORFV-RD was compared using DNASTAR software. Furthermore, the nucleotide sequence homology comparison, gene-based phylogenetic analysis and amino acid sequence homology comparison between the gene sequences obtained in this study and corresponding gene sequences from 13 ORFV whole genome sequences published on NCBI were carried out. The results showed that the nucleotide sequence homology of the B2L, F1L and VIR genes between the sequences obtained in this study and the reference sequences was 92.1%-98.4%, 96.1%-99.1%, and 94.6%-100%, respectively. The amino acid sequence homology analysis demonstrated that there were no obvious differences between ORFV-QD and ORFV-RD.

Pigeon Newcastle disease （ND） is an infectious disease caused by Newcastle disease virus （NDV）, which is prevalent in pigeon farms all over the world. This paper introduces the epidemic status and characteristics of pigeon ND, the genotypes of the NDV strains dominantly prevalent in pigeons, the virulence and antigenic feature of the NDV strains. Furthermore, we propose that, on the basis of good biosafety control and fine management in pigeon farms, the proper immunization is an effective way to the prevention and control of pigeon ND by using commercially available vaccines.

To improve the training quality of undergraduates in animal and plant quarantine specialty, taking Anhui Science and Technology University as an example, this paper investigates the current situation of this specialty targeting related industries, enterprises, universities and graduates. Based on the feedback information from the investigation, this paper puts forward the orientation of the training objectives of high-quality application-oriented professional talents in animal and plant quarantine who meet the needs of enterprises in related industry, and proposes some suggestions on revising and adjusting the curriculum system, talents training mode, practical teaching link, and teaching staff construction, in hoping to provide references for perfecting the professional talents training program of animal and plant quarantine specialty and improving the quality of talents training.

According to the demand for training application-oriented talents, the practical teaching of the animal production major of Heilongjiang Bayi Agricultural University were reformed. By revising of training plan and strengthening the practical teaching bases construction, the practical teaching was vigorously promoted; through building a team of practical type teaching staffs, the construction of practical teaching staffs was continuously strengthened; through conducting the construction projects of open laboratory sharing, the undergraduates′ initiative in hosting and participating innovation and entrepreneurship projects was encouraged. Furthermore, the practical teaching assessment and management methods were revised, the measures such as assessment of practical training skills were enhanced, and the evaluation of undergraduates′ practical ability training was improved, so as to promote the application-oriented talents training in animal production major which meet the market needs. By adopting a series of measures, the teaching reform of animal production major systematically strengthens the cultivation of undergraduates′ professional scientific research skills and innovative practical ability, and also provides references for the cultivation of high-level talents in animal production associated majors in other agricultural colleges and universities.

Aiming to improve the talents training quality, on the basis of the ′Dabeinong model′ innovative talents training program, Ulanqab Vocational College strengthens the deep cooperation with enterprises and divides talents training into three levels of ′basic skills, professional skills, and comprehensive skills′. By taking a series of measures, such as reforming the talents training program, reconstructing the curriculum system, optimizing the course content, improving the assessment and evaluation mechanism of college-enterprise co-construction, and establishing the ′double-quality′ teaching team, a featured talents training model for animal husbandry and veterinary medicine specialty has been created, which is characterized by ′integration of college and enterprise, simultaneous development of industry and education, and combination of work and study′. Furthermore, the training goal of high-quality talents skilled in animal feeding and breeding, animal disease prevention and treatment, related product selling, and livestock farm manage, has been achieved.

With the rapid development of modern social economy as well as science and technology, the Internet has been widely used in various fields, bringing great convenience to people′s lives. The development of ′Internet +′ teaching model in the field of education has brought new opportunities for education and teaching reform. Aimming to stimulate the undergraduates′ learning enthusiasm and initiative, and to realize the talents training strategy of seamless connection between talents training and post demands, we have carried out the reform on resource construction, teaching methods, assessment ways and team establishment of teachers of Small Animal Disease Prevention and Control in view of the development of pet diagnosis and treatment industry and the change of undergraduates′ characteristics, and explored how to integrate Internet technology into curriculum teaching in order to improve undergraduates′ learning enthusiasm, initiative and post adaptability.