环境因素影响肉鸡生长的研究进展

就环境因素中温度、湿度、有害气体、光照和饲养密度对肉鸡生产性能的不利影响进行综述,并从内分泌、细胞体液反应、免疫、组织器官和营养代谢角度阐明不利因素影响肉鸡生产效果的机理。     

缓释复方免疫增强剂对鸡新城疫疫苗免疫增强效果研究

将40只10日龄海兰褐蛋雏鸡，随机分成试验组和对照组，每组20只，分别皮下注射ND-La Sota弱毒疫苗0．2ml／只。同时给试验组雏鸡投服缓释复方免疫增强剂1粒／只，对照组不投服。在免疫前、免疫后10、20、30和40d，每组随机取10只鸡采血，测定ND-HI抗体效价、T淋巴细胞ERFC形成率和ANAE阳性率。结果免疫后10、20、30、40d，试验组与对照组比较，鸡ND-HI抗体效价、T淋巴细胞ERFC形成率和ANAE阳性率差异极显著（P〈0．01）或显著（P〈0．05），三项指标具有相同的消涨趋势，表明缓释复方免疫增强剂可以提高鸡的体液免疫功能和细胞免疫功能。     

藏鸡、茶花鸡染色体核型分析

运用改进的鸡外周血淋巴细胞培养-空气干燥法,分析了藏鸡、茶花鸡染色体核型.研究结果表明:藏鸡和茶花鸡的染色体形态十分相近,染色体2n众数均为78,但No.4、No.6染色体的形态存在一定的差别,即藏鸡分别为sm和m型,而茶花鸡分别为st和sm型.同时收集丝羽乌骨鸡、鹿苑鸡、狼山鸡、萧山鸡、北京油鸡的核型资料进行分析,发现鸟类核型进化可能是由不对称向对称发展的,着丝粒以及着丝粒周边区域的染色体重排可能是地方鸡种分化和形成的重要内在因素.     

文昌鸡产蛋性能及蛋品质研究

本文就文昌鸡产蛋规律、种蛋品质进行研究.结果表明:文昌鸡开产后第7周前产蛋率快速上升,到开产后第7周或第8周,产蛋率到达最高峰,60%以上的产蛋率能维持15～18周,经过产蛋高峰期后,产蛋率缓慢下降,期间略有波动,说明文昌鸡的产蛋性能良好;文昌鸡55周龄蛋品质性状蛋重(EW)、蛋壳重(SW)、蛋壳厚度(ST)、蛋壳强度(SS)、哈氏单位(HU)、蛋形指数(SI)、蛋黄重(YW)、蛋黄颜色(YC)的测定结果平均值分别为49.00g、6.34 g、320.69μm、4.01 kg/cm2.70.02、1.31、16.45 g、6.13.     

四氯联苯对鸡胚性腺原始生殖细胞的毒性影响

采用四氯联苯处理发育至Ⅹ期的白来航鸡种蛋,孵化5.5天后取出胚胎进行全固定,用石蜡切片和PAS染色(高碘酸希夫试剂)研究四氯联苯对鸡胚性腺原始生殖细胞(PGCs)的影响.结果表明,四氯联苯对发育至5.5日胚龄的鸡胚性腺PGCs数量和结构有明显影响,但雌二醇处理的5.5日胚龄鸡胚PGCs数量变化不显著,其结构无明显变化.表明四氯联苯对5.5日胚龄的鸡胚性腺PGCs的影响主要来自于其毒性作用.     

The Application and Research Progress of Chicken Embryo and Avian Cell Lines in Biomedicine

Chicken embryo has long been an important experimental model in basic and applied science because of its clear development process,especially in the early development of chicken embryo chorioallantoic membrane stage,due to its abundant blood vessels,it is a natural immunodeficiency host and can be used as an ideal experimental model for pathology,pharmacology and oncology research.The authors briefly described the tissue structure of early stage of chicken embryo,the application of chick embryo chorioallantoic membrane model in tumor,angiogenesis,organ transplantation,burn and other diseases,and the application of anti-cancer drug screening based on the pathological model of chicken embryo.The advances in the application of chicken embryo and avian cell lines in virus reproduction,vaccine production,therapeutic protein production and monoclonal antibody production were reviewed.A variety of human viruses,avian viruses and mycoplasma can proliferate in chicken embryos and avian cell lines and be used in vaccine production.In this paper,the development and characteristics of commonly used avian fibroblasts and pluripotent stem cells were described,and the source of commercial avian cell lines and some susceptible viruses were summarized.Chicken embryo expression system can produce human glycosylates at specific sites of target proteins,reduce the allergic reaction of the target protein to human,and poultry eggs are cheap and easily available,so it can be used as a suitable donor for the production of human monoclonal antibodies and therapeutic proteins.In this paper,the recent progress in the application of chicken embryos and avian cell lines in the field of biomedicine was introduced,and the future application of chicken embryos as animal models was forecasted.     

Evaluation of a Competitive Exclusion Culture and Megan Vac 1 on Salmonella Typhimurium Colonization in Neonatal Broiler Chickens

The present study was designed to evaluate the effect of individual or simultaneous application of 2 products, a competitive exclusion culture (CEC) or Megan Vac 1 (MV), for bioefficacy in reducing Salmonella Typhimurium (ST) cecal colonization in broiler chicks following experimental challenge. In experiment 1, CEC and MV were applied to day-of-hatch broiler chicks, and chicks were experimentally challenged with ST approximately 48 h later. In control chicks, ST was recovered at a level of 3.84 log₁₀ cfu/g following direct plating of cecal contents, and 12 of 19 (63.15%) cultured individual ceca were positive following selective enrichment. In chicks receiving CEC by spray application on day of hatch, a numerical reduction in ST recovered from cecal contents (2.63 log₁₀ cfu/g) and a significant reduction (P < 0.05) in recovery of ST from cultured ceca following selective enrichment (4 of 18, or 22.2%) was observed when compared with controls. Significant reductions in ST cecal colonization in chicks treated with MV alone were not observed in experiment 1. In experiment 2, chicks received day-of-hatch spray application of CEC alone, MV alone, or CEC and MV as a combined application immediately prior to or within 24 h of chick placement. When chicks were experimentally challenged with ST 48 h posthatch, significant reductions (P < 0.05) in cecal colonization by ST were observed with each experimental group when compared with nontreated controls. These data suggest that both commercially available products, alone or in combination, are efficacious in reducing cecal colonization in broiler chicks challenged with ST.     

黄羽肉鸡IGF-1基因单核苷酸多态性与生长性状的相关研究

本试验将类胰岛素生长因子1(IGF-1)作为研究肉鸡生长的候选基因,以海门京海集团的第二世代黄羽肉鸡为试验材料,根据鸡IGF-1基因DNA序列设计引物,采用PCR-SSCP方法进行SNP检测和基因型分析,探讨IGF-1基因多态性与鸡生长性状之间的关系。于IGF-1基因外显子1上发现一处突变。这个突变产生的不同基因型与鸡生长性状进行的统计分析结果表明,个体的1日龄初生重、4周龄、12周龄及300日龄成年体重在不同基因型之间均存在显著差异(P<0.05)。AA基因型1日龄初生重、4周龄、8周龄及300日龄成年体重均显著高于BB基因型个体(P<0.05)。推测可以将IGF-1基因应用于鸡生长的标记辅助选择育种实践。     

肉鸡能量需要动态模型的建立和参数估计

本研究通过两个试验评价肉仔鸡的能量需要。试验1选用36只AA肉仔鸡新生雏笼养6周,分别于3周龄和6周龄评定2种饲粮的表观代谢能(AME)和表观氮校正代谢能(AMEn)。结果表明:氮校正使AME降低5%左右,AMEn和AME的相关性较强。试验2选用AA肉鸡新生雏240只,公母分饲笼养6周,每周测定空腹体重及采食量。用Compertz方程拟合公母鸡的生长曲线,微分建立日增重与日龄的函数关系,再与利用一元线性回归法建立的能量需要模型组合,形成动态的能量需要预测机制。