云岭黑山羊及波云F_1代的育肥性能研究

为比较云岭黑山羊和波云F1代肉羊的产肉性能和肉质特性,为今后云南省的羔羊肉生产提供科学依据,选90只3月龄断奶的波尔山羊×师宗黑山羊（波×师）、波尔山羊×文山黑山羊（波×文）、波尔山羊×楚雄黑山羊（波×楚）F1代的去势公羔和师宗黑山羊、文山黑山羊、楚雄黑山羊的去势公羔进行育肥,育肥期为180 d;抽取6只羊进行屠宰测定与肉质分析。结果表明：在＂放牧＋补饲＂条件下,波云F1代的平均日增重（ADG）明显好于相应本地羊,差异极显著（P〈0.01）。在三个杂交组合中,波×师组的ADG比波×文组和波×楚组高,差异显著（P〈0.05）;在三个纯繁群间的ADG差异不显著（P〉0.05）,说明波×师组合生产速度更快,具有较好的遗传特性,应该作为重点培育的杂交组合类型;在全放牧条件下,波云F1代的ADG与相应纯繁后代比较,差异不显著（P〉0.05）;在＂放牧＋补饲＂条件下,杂交组合的胴体重、净肉重显著高于相应的本地品种,差异显著（P〈0.05）;在全放牧条件下,杂交组合的胴体重、净肉重也高于对应的本地品种,差异不显著（P〉0.05）。杂交组合与本地品种的肉质成份无太大差别。综合看来,＂放牧＋补饲＂方式下以波×师组合为生产肥羔的最佳组合。     

Prior infection with antigenically heterologous low pathogenic avian influenza viruses interferes with the lethality of the H5 highly pathogenic strain in domestic ducks

Low and highly pathogenic avian influenza viruses (LPAIVs and HPAIVs, respectively) have been co-circulating in poultry populations in Asian, Middle Eastern, and African countries. In our avian-flu surveillance in Vietnamese domestic ducks, viral genes of LPAIV and HPAIV have been frequently detected in the same individual. To assess the influence of LPAIV on the pathogenicity of H5 HPAIV in domestic ducks, an experimental co-infection study was performed. One-week-old domestic ducks were inoculated intranasally and orally with phosphate-buffered saline (PBS) (control) or 10⁶ EID₅₀ of LPAIVs (A/duck/Vietnam/LBM678/2014 (H6N6) or A/Muscovy duck/Vietnam/LBM694/2014 (H9N2)). Seven days later, these ducks were inoculated with HPAIV (A/Muscovy duck/Vietnam/LBM808/2015 (H5N6)) in the same manner. The respective survival rates were 100% and 50% in ducks pre-infected with LBM694 or LBM678 strains and both higher than the survival of the control group (25%). The virus titers in oral/cloacal swabs of each LPAIV pre-inoculation group were significantly lower at 3–5 days post-HPAIV inoculation. Notably, almost no virus was detected in swabs from surviving individuals of the LBM678 pre-inoculation group. Antigenic cross-reactivity among the viruses was not observed in the neutralization test. These results suggest that pre-infection with LPAIV attenuates the pathogenicity of HPAIV in domestic ducks, which might be explained by innate and/or cell-mediated immunity induced by the initial infection with LPAIV.     

引进肉用绵羊品种的杂交利用研究进展

文章综述了从国外引进优良肉用绵羊品种对国内不同地方绵羊品种杂交改良方面的研究应用情况,重点介绍了萨福克羊、杜泊羊、无角陶赛特羊、美利奴羊、特克塞尔羊等优良绵羊品种与我国不同地方绵羊品种杂交,其杂交后代在生长发育性能、产肉性能、胴体品质等方面的表现,旨在总结中国肉用绵羊的杂交改良工作,为推动中国肉用绵羊杂交改良,提高地方绵羊的生长性能和肉用性能,扩大我国肉羊的生产规模,促进我国畜牧业的健康发展和动物性肉食结构平衡提供借鉴。     

复方中草药添加剂对稻鸭共作模式下成都麻鸭生理效应的影响研究

为研究复方中草药添加剂对稻鸭共作模式下成都麻鸭生长性能、血清生化指标、抗氧化指标及免疫指标的影响,试验选取体重相近、体况健康的15日龄成都麻鸭240只,随机分为4组,每组5个重复,每个重复12只。4组为对照组饲喂基础饲粮;试验1、2、3组在基础饲粮中按照质量比分别添加0.5%(低剂量组)、1%(中剂量组)、2%(高剂量组)的复方中草药,试验期90 d。结果显示:(1)试验1、2、3组的平均日增重分别较对照组提高2.19%、4.34%、4.98%(P<0.05);试验2、3组的料重比分别较对照组降低3.37%、3.63%(P<0.05);(2)试验2组和3组的总蛋白(TP)分别较对照组提高4.20%、6.08%(P<0.05);试验2组和3组的尿素氮(BUN)分别较对照组降低12.72%、16.36%(P<0.05);试验2组和3组的谷草转氨酶(ALT)分别较对照组降低15.84%、19.22%(P<0.05);试验3组的谷丙转氨酶(AST)较对照组降低19.34%(P<0.05);(3)试验2组和3组超氧化物歧化酶(SOD)分别较对照组提高15.80%、20.00%(P<0.05);试验3组的总抗氧化能力(T-AOC)较对照组提高22.37%(P<0.05);(4)三个试验组的IgA、IgM、IgG、IFN-γ、IL-2显著高于对照组(P<0.05),试验2组的肿瘤坏死因子-α(TNF-α)较对照组提高10.06%(P<0.05),试验2组和3的组溶菌酶(LZM)分别较对照组提高6.79%、5.66%(P<0.05)。综上,中草药添加剂能有效提高稻鸭共作模式下成都麻鸭的生长性能、血清生化指标、抗氧化指标及免疫指标,本试验条件下,最佳饲喂剂量为1%。     

Effect of dietary supplemental nicotinic acid on growth performance,carcass characteristics and meat quality in three genotypes of chicken

The effects of dietary supplemental nicotinic acid (NA) on growth performance, carcass characteristics and meat quality were investigated in three genotypes of chicken. Fast‐growing AA (Arbor Acres) broilers were compared with two genotypes of a slow‐growing local breed, Beijing‐You, that had undergone selection for and against intramuscular fat content respectively (BJY+IMF and BJY?IMF). The treatments were arranged 3 × 4 factorial completely randomized design. Day‐old females (n = 624) were allocated to four treatments with six replicates per treatment and fed diets (basal contained ～25 mg NA/kg) supplemented with 0, 30, 60 and 120 mg NA/kg. A sample of 72 birds from each genotype was slaughtered at market time (8 weeks of age for AA and 16 weeks of age for BJY). The breast muscles of AA broilers were darker, had less redness and yellowness, lower drip loss and higher shear force as compared to the BJY genotypes (p < 0.01). The highest drip loss and the lowest shear force among the three genotypes were apparent in BJY+IMF (p < 0.01). Increasing supplementation from 0 to 60 mg NA/kg tended to increase average daily gain (ADG), average daily feed intake, width of intermuscular fat band, thickness of subcutaneous fat (including skin) and percentage of abdominal fat but, for most variables, values decreased slightly with 120 mg NA/kg. Increasing supplementation to 60 mg NA/kg decreased (quadratic, p < 0.001) drip loss, but it increased at 120 mg NA/kg. The present results indicate that (i) the AA broilers fed corn–soybean meal based‐diets require approximately 60 mg NA/kg to maximize ADG and meat product yield and decrease the drip loss of breast muscle; (ii) the addition of 30 mg NA/kg meets the requirement of BJY genotypes; and (iii) there seems to be no beneficial effect of NA supplementation on chicken meat quality except for limiting the drip loss.     

鸭肠炎病毒NP蛋白的原核表达及间接ELISA方法的建立

设计一对特异性引物扩增出鸭肠炎病毒(DEV)核衣壳蛋白(NP)基因,并将其定向插入到原核表达载体pET32a上,构建了NP基因的原核表达载体pET-NP;将重组载体pET-NP转化表达宿主菌BL21后,经SDS-PAGE分离后行Western blot显示,获得的表达产物具有良好的免疫原性;应用His.Bind亲和层析柱纯化重组NP蛋白,并以此作为包被抗原,初步建立了检测鸭肠炎病毒抗体的iNP-ELISA;经方阵滴定确定,重组蛋白抗原的最佳包被浓度为5.0μg/L,血清最佳稀释度为1∶80,阳性判定标准为:待检血清OD405值≥1.2,且待检血清OD405和阴性血清OD405的比值≥2.0;应用iNP-ELISA对450份鸭血清样本进行检测,结果iNP-ELISA与全病毒包被的iDEV-ELISA符合率达90.9%。     

妊娠后期母猪和仔猪补饲外源精胺对初生和28日龄仔猪肠道形态结构及二糖酶活性的影响

本文通过研究妊娠后期母猪和仔猪补饲外源精胺对初生和28日龄仔猪肠道形态结构和二糖酶活性的影响,初步探讨干预“仔猪早期断奶综合征”的技术措施.试验第1阶段,选择6头体重和膘情相近、胎次为3、已怀孕91 d的健康“长×大”母猪,随机分为Ⅰ、Ⅱ和Ⅲ3个组,每个组设2个重复,每个重复1头母猪.Ⅰ、Ⅱ和Ⅲ组妊娠母猪饲粮中外源精胺的添加量为0、1.5和3.0 mg/kg,饲喂至分娩结束;第2阶段,分娩后母猪采食同一种不含外源精胺的饲粮,Ⅰ、Ⅱ和Ⅲ组哺乳仔猪于7日龄起相应补饲外源精胺添加量为0、3.0和6.0 mg/kg的哺乳仔猪饲粮至28日龄.在仔猪初生和28日龄时,分别从每窝仔猪中选1头接近平均体重的健康仔猪进行屠宰,用于胃肠发育指标的测定.结果表明:与未添加外源精胺相比,妊娠母猪饲粮添加3.0 mg/kg外源精胺显著提高了初生仔猪十二指肠和回肠的柱状细胞数量、十二指肠和空肠的杯状细胞数量(P＜0.05),显著增加了空肠隐窝深度(P＜0.05),显著提高了麦芽糖酶和蔗糖酶比活力(P＜0.05);哺乳仔猪饲粮添加6.0 mg/kg外源精胺显著增加了28日龄仔猪空肠黏膜重(P＜0.05),显著提高了十二指肠和空肠的麦芽糖酶和蔗糖酶比活力(P＜0.05),极显著增加了空肠柱状细胞和杯状细胞数量(P＜0.01),极显著增加了十二指肠和空肠隐窝深度(P＜0.01).因此,在妊娠后期母猪和哺乳仔猪饲粮中添加外源精胺有利于初生和28日龄仔猪肠道形态结构的改善和二糖酶活性的提高.     

中国地方鸭遗传资源的分子评估与保护利用

论文从分子遗传学的角度对鸭的遗传资源在群体遗传多样性、群体起源、进化及构建遗传图谱等多个方面的评估进行综述,并对分子遗传标记技术在鸭遗传资源的保护利用上的应用进行概述,以期通过现代动物分子育种技术加快鸭的育种进程。     

牛肉品质蛋白质组学研究进展

蛋白质组学是后基因组时代出现的一个新研究领域。中国牛肉目前仍需要大量进口,提高牛肉肉品质一直是我国畜牧和食品行业科研工作者尽心研究的一大课题。随着基因组学的发展,从蛋白质水平研究肉品质及形成机理,对提高肉品质有着重要的意义。肌肉主要由水及蛋白质等成分组成,且肌肉的性状以及品质主要就是由蛋白质来表达的。因此,研究牛肉蛋白质组学对认知以及调控牛肉的品质具有重要意义。本文主要对蛋白质组学的研究技术及其在牛肉品质研究中的应用做简要介绍。