植酸酶对肉鸡生产性能和胴体品质及肉质性状的影响

为了研究植酸酶不同添加量对肉鸡生长和胴体品质的影响。选择2周龄青脚麻鸡142只,随机分成4组。试验Ⅰ组、Ⅱ组和Ⅲ组用500g/t植酸酶分别代替60%、70%和80%的磷酸氢钙,试验Ⅳ组为对照组。试验结果表明:用植酸酶取代60%的磷酸氢钙,肉鸡的日增重和饲料报酬均优于其它试验组和对照组(P<0.05)。添加植酸酶后,肉鸡的屠宰率、全净膛率、半净膛率、腿比率和胸肌率与对照组相比较无显著差异;熟肉率、滴水损失率等肉质指标与对照组比较亦差异不显著,而肉的嫩度第Ⅲ组劣于其它各组。综上所述,在肉鸡日粮中以500g/t的植酸酶代替60%的磷酸氢钙可以提高肉鸡的生长性能,是最佳的替代比例。而对屠宰性能和肉质无明显影响。     

矮小型基因对地方鸡种肉用性能影响

对来源于遗传基础相同且含地方鸡种血缘的矮小型（ｄｗ）叫和正常型（ＤＷ）后代的早期生长、饲料报酬、体尺和屠宰性状进行比较。结果显示：１４周龄时ｄｗ后代母鸡的体重为ＤＷ后代鸡的９６％～１００％，公鸡为９５％～９６％；ｄｗ后代鸡的存活率高２％～３％；ｄｗ基因对后代肉鸡的饲料报酬、主要体尺和屠宰性状无显著影响。     

鸡白细胞介素2(IL-2)对鸡免疫功能的影响

为研究鸡IL-2对雏鸡免疫功能的影响，进行了3个方面的试验。①对体液免疫及细胞免疫的影响。结果表明，鸡IL-2能明显提高鸡新城疫疫苗免疫后HI水平、T淋巴细胞增殖反应及ANAE^＋细胞百分数；②对雏鸡腹腔巨噬细胞吞噬功能的影响。结果表明使用IL-2与否对巨噬细胞的吞噬功能没有明显的影响；⑧人工感染法氏囊病的防治试验。在攻毒前后注射IL-2，均可明显降低发病率和死亡率。本研究结果表明，鸡IL-2可明显提高特异性免疫应答能力，与疫苗共同注射可作为佐剂提高疫苗的免疫原性，对法氏囊等病毒性疾病具有一定的防治作用。     

利用原位二步灌流法分离鸡肝细胞

试验选用15~18日龄的粤黄鸡苗,采用胶原酶原位二步灌流的方法分离肝细胞。对小鸡破坏大脑处死后,打开腹腔,先用PBS液对小鸡进行门静脉快速灌流,当肝脏呈现苍白略带黄色时改用Ⅳ型胶原酶溶液继续灌流,直至肝包膜与肝组织出现裂隙,即可分离出肝细胞。结果表明:用原位二步灌流法可得到大量活性高且分离较纯的鸡肝细胞。     

中国6个地方鸡品种的母系起源

通过对线粒体DNA（mtDNA）D-loop区的测序和比对,探讨了中国6个地方鸡品种的母系起源。结果表明,文昌鸡、鲁西斗鸡、寿光鸡、济宁百日鸡和莱芜黑鸡分别有5、5、5、6和7种单倍型,琅琊鸡只有3种单倍型;6个地方鸡品种聚为3个分支：分支A是1个主要分支,共有17种单倍型,有寿光鸡（10只）、鲁西斗鸡（9只）、文昌鸡（5只）、莱芜黑鸡（6只）、济宁百日鸡（6只）和琅琊鸡（2只）,分别占所分析各地方鸡品种个体数的100%、90%、84%、75%、60%和20%,与分布于老挝、云南红原鸡的3个大陆亚种（G.g.gallus、G.g.jabouile和G.g.spadi-ceus）关系较近;分支B中包含8只琅琊鸡（80%）和1只济宁百日鸡（10%）;分支C中有1只鲁西斗鸡（10%）、1只文昌鸡（16.7%）、2只莱芜黑鸡（25%）和3只济宁百日鸡（30%）;分支B和C分别与来自红原鸡G.g.gallus亚种H19单倍型和H32、H33单倍型聚在一起。推测这6个地方鸡品种分别来自云南、老挝和越南附近地区的红原鸡大陆亚种。基因流是上述品种群体间遗传分化的主要因素。错配分布和Fu＇sFs检验表明,分布于山东的5个地方鸡品种未发生群体扩张。     

鸡血管活性肠肽RNA探针制备及其在鸡肠Remak神经的原位杂交反应

应用RT-PCR方法从鸡脑中扩增血管活性肠肽(VIP)基因片段,将其连接于pGM-T easy.分别利用pGM-T easy中T7和SP6启动子及其RNA聚合酶,以线性化的VIP/pGM-T easy为模板转录合成正、反义DIG标记RNA探针.通过原位杂交方法将合成的探针用于探查VIP-mRNA在鸡肠Remak神经(INR)中的分布情况.结果表明,INR的神经元胞体中有VIP-mRNA的转录,且这种神经元数量众多;原位杂交阳性神经元胞体大部分是大型神经元细胞,呈圆形或椭圆形;阳性神经元胞体在INR神经节中呈层状或成群分布.INR的神经纤维呈弱阳性.在节间束也有少量的阳性细胞分布.本研究从基因水平证明INR中有VIP神经元存在.     

鸡致病性大肠杆菌对头孢喹肟等的体外敏感性

从2006年1月~6月河南省中北部8个地级市鸡场的发病或死亡鸡分离细菌，选取经生化和动物试验结果证明的鸡致病性大肠杆菌共63株，采用肉汤稀释法测定其对头孢喹肟、头孢噻呋、氟苯尼考和沙拉沙星的敏感性。结果显示，试验菌对以上药物的耐药率分别为33.3%、46.0%、63.5%和98.4%。鸡致病性大肠杆菌对几种较新的动物专用抗生素耐药性状况不容忽视。     

纳米铜、灵芝孢子粉与大豆异黄酮对1~30日龄清远麻鸡生长、免疫及抗氧化性能的影响

本研究对比分析了饲粮中添加纳米铜、灵芝孢子粉与大豆异黄酮对育雏阶段清远麻鸡生长性能、免疫功能及抗氧化性能的影响，旨在为肉鸡生产中添加剂的开发及应用提供参考。采用单因素随机分组设计，选用1 200只1日龄清远麻鸡母鸡分成4组，对照组（CON）饲喂基础饲粮，3个处理组（NC、GLS及SI）分别在基础饲粮中添加2 500 mg/kg纳米铜、600 mg/kg灵芝孢子粉和300 mg/kg大豆异黄酮预混剂。每个处理10个重复，每个重复30只鸡，试验期30天。试验结束后，采集试验鸡血浆、空肠黏膜样品，测定血液抗氧化相关生化指标及肠道免疫因子。结果表明：与对照组相比，①饲粮添加纳米铜、灵芝孢子粉与大豆异黄酮对清远麻鸡肉仔鸡的生长性能均无显著影响（P>0.05）。②灵芝孢子粉显著提高了30日龄清远麻鸡的胸腺比例（P<0.05）。③纳米铜显著提高了清远麻鸡的空肠绒毛隐窝比（P<0.05）。④纳米铜、灵芝孢子粉与大豆异黄酮均显著增加了清远麻鸡血浆和空肠中总超氧化物歧化酶（T-SOD）活性（P<0.05）；纳米铜显著增加了血浆谷胱甘肽过氧化氢酶（GSH-Px）活性（P<0.05）、降低了空肠黏膜丙二醛（MDA）含量（P<0.05）；大豆异黄酮显著降低血浆与空肠MDA含量（P<0.05）。⑤纳米铜组清远麻鸡空肠中免疫球蛋白A（IgA）含量显著增加（P<0.05），灵芝孢子粉组清远麻鸡血浆中肿瘤坏死因子-α（TNF-α）、空肠中干扰素-γ（IFN-γ）含量显著降低（P<0.05）。在本试验条件下，纳米铜、灵芝孢子粉与大豆异黄酮对清远麻鸡肉仔鸡生长性能没有显著影响，但均可改善抗氧化性能指标；纳米铜可提高空肠绒毛隐窝比，纳米铜与灵芝孢子粉可调节免疫因子分泌。其中纳米铜对抗氧化性能的调节作用最优，灵芝孢子粉对免疫功能调节作用最优。     

Practical Application of Miyazaki Jitokko Chickens Selected for a Superior Allele at a Single Nucleotide Polymorphism Site in the Cholecystokinin Type A Receptor Gene

This study aimed to examine 1) whether selection for a superior allele at a single nucleotide polymorphism site (SNP; {"type":"entrez-nucleotide","attrs":{"text":"AB604331","term_id":"315258605","term_text":"AB604331"}}AB604331, g.420 C>A) of the chicken cholecystokinin type A receptor (CCKAR) gene in Miyazaki Jitokko chickens is detectable in commercial poultry farms, and 2) whether the reproductive traits of the Kyushu Rhode hens, as a maternal stock line of the Miyazaki Jitokko chickens, are affected by SNP selection. Conventional and A-allele fixed (improved) Miyazaki Jitokko chicks were hatched on the same day and raised in a battery cage until 7 days of age. The chicks were then deposited at two commercial poultry farms and reared until slaughter at 126 and 163 days for cockerels and pullets, respectively. Body weight on the day of hatching (day 0), at 5 days of age, and at slaughter were measured. The differences in the body weights of the farm and test groups at slaughter were analyzed using the generalized linear model. A-allele fixation increased the body weight at slaughter by approximately +123.5 g and +131.9 g in cockerels and pullets, respectively. No significant differences between the conventional and improved hens were detected in terms of egg-laying rate, fertilization rate, and hatchability in the Kyushu Rhode hens. The data suggest that fattening chicks can be supplied as usual, even if Kyushu Rhode hens are switched from the conventional to improved type. In conclusion, genetic improvements using the CCKAR SNP site as a marker were effectively established in terms of the growth of the Miyazaki Jitokko chickens in commercial farms and the reproductive traits of the Kyushu Rhode hens.     

Dietary supplementation of essential oils and lysozyme reduces mortality and improves intestinal integrity of broiler chickens with necrotic enteritis

The objective of this study was to investigate the individual and combined effects of essential oils (EO; comprised of thymol and carvacrol) and lysozyme on experimental NE in broiler chickens. A total of 320 1-day-old chicks were randomly assigned to five treatment groups: no-challenge control (NC), NC + C. perfringens challenge (CC), CC + 120 mg/kg of EO, CC + 100 mg/kg of lysozyme, and CC + 120 mg/kg of EO + 100 mg/kg of lysozyme. The results showed that EO or lysozyme decreased the mortality, alleviated the gut lesions, inhibited the liver Enterobacteriaceae carriage, and increased the villus height of the ileum compared with CC (p < .05), although the proliferation of C. perfringens in the ileum was not inhibited (p > .05). Moreover, EO or lysozyme was found to decrease the ileal concentration of sialic acid and the Mucin2 mRNA expression (p < .05). However, the blend of EO and lysozyme did not display significant effect on the NE-associated mortality or gut damage in contrast with CC (p > .05). In conclusion, these findings suggest the similar protective effects of EO and lysozyme in NE-associated mortality and intestinal impairment, but their blend did not exhibit ameliorative effect.