中国野牦牛种质资源库体系的建立及利用

介绍构建野牦牛种质资源信息收集、整理及调查的方法;建立了野牦牛50头规模的可良性运作的遗传繁育基地，可年产2万支冷冻精液的动态保存库，以及0.1万～0.15万枚野牦牛冷冻胚胎动态保存库的条件与规模;创建了国内外相关野生动物保护组织、行业、协会等保护和利用野牦牛遗传资源的共享平台.     

鸭流感病毒4/2004-H6N2亚型毒株的血凝素基因全序列克隆与分析

2004初从正常鸭群中分离到一株鸭源禽流感病毒，命名为A／Duck／HN／4／2004(H6N2)。经对血凝素基因(HA)序列分析发现HA基因全长为1744bp，共编码566个氨基酸，在裂解位点仅含一个碱性氨基酸-精氨酸(R)，符合LPAIV的标准。将所得基因序列与已发表的同一亚型参考序列分析表明，与H6亚型流感HA基因同源性为89．2％-97．1％，经分子遗传演化分析表明本次分离株与香港分离株A／Duck／Hong Kong／3600／99(H6N2)、A／Duck／Hong Kong／3600／99(H6N2)最近。     

血清中IBV特异性IgG及总IgG含量变化规律的研究

本研究采用间接酶联免疫吸附试验对人工感染鸡传染性支气管炎病毒的SPF鸡血清中特异性抗体及总IgG含量进行检测并比较其相关性.结果表明感染IBV-M41第1 d、3 d、5 d、7 d、10d、14d、21 d、28 d的血清中特异性抗体水平随感染天数增加而升高,于第14天达到最高,之后略呈降低趋势,与健康对照比较差异显著(P＜0.01);总IgG含量较健康对照组增幅小,差异显著(P＜0.01).同时,两者的消长趋势基本一致.     

出血性大肠杆菌O157eae-stx1/2B融合基因的构建和表达

构建表达eae和stx1／2B的融合基因，克隆eae基因的C端280个氨基酸残基(Int280)基因部分，以正确地阅读框定向插入到含有stx1／2B融合基因的质粒，构建重组质粒，将其转化于BL21(DE3)，用IPTG进行诱导表达，经SDS—PAGE电泳检测，该融合蛋白获得了高效表达。薄层扫描分析表明：目的蛋白表达量占菌体总蛋白含量的50．67％。由于该融合蛋白由eae、stx1B、stx2B等三部分抗原组成，可刺激机体产生针对紧密素和StxB的抗体，在EHEC O157亚单位疫苗设计或单克隆抗体抗制备中具有重要价值。     

混合比例和添加剂对菊苣与青贮玉米混合青贮品质的影响

探讨不同混合比例和添加剂对菊苣和青贮玉米混合青贮饲料品质的影响,为调制高质量的混合青贮饲料提供理论依据。以菊苣和青贮玉米为原料,按质量比0∶1、1∶3、1∶1、3∶1和1∶0 (分别用0C1M、1C3M、1C1M、3C1M、1C0M表示)进行混合青贮,并分别设置3个添加剂处理,即零添加、5 g·t^-1乳酸菌+5 g·t^-1纤维素酶(LX)和10 g·t^-1乳酸菌+5 g·t^-1纤维素酶(2LX),青贮60 d后测定混合青贮饲料的营养成分和发酵品质。结果显示,菊苣与青贮玉米混合比例为0∶1和1∶1时青贮饲料的感官评价优于其余3种混合比例的,而且添加剂处理感官评定优于零添加处理的。菊苣和青贮玉米混合青贮可以形成养分互补,有助于均衡青贮饲料整体营养,在青贮原料中添加添加剂则可以提高青贮饲料发酵品质。混合青贮饲料的营养价值随菊苣比例增加而显著提高,但是发酵品质在菊苣混合青贮比例高于1∶1时显著降低。综合判定菊苣和青贮玉米1∶1混合时其青贮饲料品质最佳,其中又以1C1M/2LX处理最好,纤维组分(NDF和ADF)和氨态氮/总氮含量较低而粗蛋白和乳酸含量较高。     

The complete mitochondrial genome and molecular phylogeny of Lueyang black-bone chicken

ABSTRACT

1. The objectives of the current study were to investigate the mitochondrial genome and molecular phylogeny of Lueyang black-bone chicken, and provide molecule base to preserve and explore the specific chicken strain.

2. Based on sequencing and clustering, the complete mitochondrial DNA map and sequences of Lueyang black-bone chicken were revealed, and two phylogenetic trees of Lueyang black-bone chickens based on D-loop sequences and the mitochondrial genome were constructed.

3. The results showed that the complete mitochondrial genome of Lueyang black-bone chickens is 16,784bp in size, consisting of 22 transfer RNA genes, two ribosomal RNA genes, 13 protein-coding genes, and one non-coding control region. The base composition of the complete mtDNA sequence is 30.28% for A, 23.78% for T, 32.42% for C, 13.52% for G. Additionally, 10 haplotypes of D-loop sequences in 32 Lueyang black-bone chickens were detected, which were distributed into 4 clades (A, B, C and E).

4. It was concluded that genetic diversity is wide in Lueyang black-bone chickens, and this strain has multiple maternal origins from different regions in China and neighbouring regions.     

Effect of heat stress on the behavioral and physiological patterns of Small-tail Han sheep housed indoors

Tropical Animal Health and Production - This study was conducted to investigate the effects of heat stress on the behavioral and physiological patterns in Small-tail Han sheep housed indoors in...     

Modulation of broilers’ caecal microflora and metabolites in response to a potential probiotic Bacillus amyloliquefaciens

Studies have found that a dietary supplement of Bacillus amyloliquefaciens improved the growth performance, increased the nutrient digestibility of hosts and modulated the intestinal microflora. A total of 360 1‐day‐old Ross broilers were randomly divided into three treatments: a control group with a basal diet, an antibiotic group with a basal diet and added colistin sulphate, and a probiotics group with a basal diet and added Bacillus amyloliquefaciens. The HiSeq high‐throughput sequencing analysis of 16S rRNA was used to investigate the differences in birds’ caecal microflora, and metabolomics was used to analyse changes in caecal metabolites. Results showed that the supplementation of Bacillus amyloliquefaciens significantly improved the BW and ADG compared with the control birds. Results of sequencing indicated that (i) 645, 670, 596 unique operational taxonomic units (OTUs) were found in birds supplemented with Bacillus amyloliquefaciens on day 7, 21 and 42, separately, (ii) due to the diversity and relative abundance of the birds’ caecal microflora, the OTUs of the caecal microflora clustered according to age and treatment, except on day 42, (iii) among the six predominate families (Ruminococcaceae, Lachnospiraceae, Enterobacteriaceae, Erysipelotrichaceae, Lactobacillaceae and Rikenellaceae), the supplementation of Bacillus amyloliquefaciens significantly increased Enterobacteriaceae on day 42, (iv) Bacillus amyloliquefaciens increased the relative abundance of Faecalibacterium and Ruminococcus on day 21, increased the Faecalibacterium and Blautia and decreased the Ruminococcus on day 42. The metabolomics of caecal metabolites showed that the dietary Bacillus amyloliquefaciens changed the caecal metabolites involved of amino acid metabolism and glyceride metabolism, and the antibiotics changed the caecal metabolites that were related to carbohydrates and amino acid metabolism on day 21.     

Methyl donors dietary supplementation to gestating sows diet improves the growth rate of offspring and is associating with changes in expression and DNA methylation of insulin‐like growth factor‐1 gene

The study aimed to investigate the effects of maternal dietary methyl donors on the performance of sows and their offspring, and the associated hepatic insulin‐like growth factor‐1 (IGF‐1) expression of the offspring. A total of 24 multiparous sows were randomly fed the control (CON) or the CON diet supplemented with methyl donors (MD) at 3 g/kg betaine, 15 mg/kg folic acid, 400 mg/kg choline and 150 μg/kg VB₁₂, from mating until delivery. After farrowing, sows were fed a common lactation diet through a 28‐days lactation period and six litters per treatment were selected to be fed until at approximately 110 kg BW. Maternal MD supplementation resulted in greater birthweight (p < 0.05) and increased the piglet weights (p < 0.01) and litter weights (p < 0.05) at the age of day 28, compared with that in CON group. The offspring pigs in the MD group had greater ADG (p < 0.05) and tended to lower F:G ratio (p = 0.07) compared with that of CON group from day 28 to 180 of age. The offspring pigs from MD group had greater serum IGF‐1 concentrations and expressions of hepatic IGF‐1 gene and muscular IGF‐1 receptor (IGF‐1r) protein at birth (p < 0.05), and greater hepatic IGF‐1 protein (p = 0.03) and muscular IGF‐1r gene expressions (p < 0.05) at slaughter, than that from the CON group. Moreover, the methylation at the promoter of IGF‐1 gene in the liver of newborn piglets and finishing pigs was greater in the MD group than that of the CON group (p < 0.05). In conclusion, maternal MD supplementation throughout gestation could enhance the birthweight and postnatal growth rate of offspring, associated with an increased expression of the IGF‐1 gene and IGF‐1r, as well as the altered DNA methylation of IGF‐1 gene promotor.     

Multimarker and rare variants genomewide association studies for bone weight in Simmental cattle

Bone weight, defined as the total weight of the bones in all the forequarter and hindquarter joints, can reflect somebody conformation traits and skeletal diseases. To gain a better understanding of the genetic determinants of bone weight, we used a composite strategy including multimarker and rare‐marker association to perform genomewide association studies (GWAS) for that character in Simmental cattle. Our strategy consisted of three models: (i) A traditional linear mixed model (LMM) was applied (Q+K‐LMM); (ii) single nucleotide polymorphisms (SNPs) with p‐values less than .05 from the LMM were selected to undergo the least absolute shrinkage and selector operator (Lasso) in the second stage (LMM‐Lasso); (iii) genes containing two or more rare SNPs were examined by performing the sequence kernel association test (gene‐based SKAT). A total of 1,225 cattle were genotyped with an Illumina BovineHD BeadChip containing 770,000 SNPs. After the quality‐control procedures, 1,217 individuals with 608,696 common SNPs and 105,787 rare SNPs (with 0.001 < minor allele frequency [MAF] <0.05) remained in the sample for analysis. A traditional LMM successfully mapped three genes associated with bone weight, while LMM‐Lasso identified nine genes, which included all genes found by traditional LMM. Only a single gene, EPHB3, surpassed the significance threshold after Bonferroni correction in gene‐based SKAT. In conclusion, based on functional annotation and results from previous endeavours, we believe that LCORL, RIMS2, LAP3, PRKAR2B, CHSY1, MAP2K6 and EPHB3 are candidate genes for bone weight. In general, such a comprehensive strategy for GWAS may be useful for researchers seeking to probe the full genetic architecture underlying economic traits in livestock.