为探究互花米草黄酮提取物对肉鸡免疫功能的影响,试验选取120只AA白羽肉鸡(又称双A鸡)随机分成4组,每组30只,Ⅰ～Ⅲ组饲喂添加互花米草黄酮提取物的基础日粮,添加剂量分别为1g/kg,1.5g/kg,2g/kg,Ⅳ组为饲喂基础日粮对照组.各组在7 d点眼滴鼻、20 d饮水免疫1头羽份的鸡新城疫(Newcastle disease,ND)La Sota+鸡传染性支气管炎(Infectious Bronchitis,IB)H120二联活疫苗,并分别于7、14、21、28、35、42d进行血清ND-Ab、IB-Ab、免疫球蛋白M(Immunoglobulin M,IgM)、免疫球蛋白 G(Immunoglobulin G,IgG)、免疫球蛋白A(Immunoglobulin A,IgA)、γ干扰素(Interferon-γ,IFN-y)、白细胞介素2(interleukin-2,IL-2)、T淋巴细胞CD4亚群(lymphocyte subpopulation CD4+)、T淋巴细胞 CD8 亚群(lymphocyte subpopulation CD8+)含量的检测和外周血中淋巴细胞转化率的测定.结果显示,添加互花米草黄酮提取物组各指标均显著高于对照组(P＜0.05);添加1.5g/kg的Ⅱ组各项指标显著高于其他各组(P＜0.05).结果表明,互花米草黄酮提取物可显著增强肉鸡的免疫效果;本试验条件下,互花米草黄酮提取物添加剂量为1.5g/kg效果最佳.

为改善商品肉鸡场养殖饮用水的卫生管理模式,研究在调研商品肉鸡场养殖饮用水卫生状况的基础上,制定"脉冲+臭氧消毒"的水线管理方案,对设备处理效果进行检测,并对设备处理频率进行初步探讨.检测中以菌落总数和总大肠菌群数作为水的卫生指标,以水源和水线的始端、中段和末端作为采样点.结果显示,92.86％(13/14)的商品肉鸡场水源水卫生达标,而水线始端样品达标率仅为14.19％(2/14),末端样品达标率则为0(0/16),表明水的二次污染不同程度地存在.在水线始端样品卫生不达标的12个鸡场中,11个(91.7％)场的水源水达标,表明存在舍外管线和储水罐对水的污染.采用"脉冲+臭氧消毒"设备对水线进行处理,处理前后水线始端、中段和末端水样的检测结果显示,该设备对水线水的菌落总数和总大肠菌群数消除率均大于96％.研究提示,"脉冲+臭氧消毒"设备对改善二次污染的养殖饮用水具有很好的效果,在肉鸡养殖过程中,利用该设备对水线进行处理的间隔时间为4 d是安全可行的.

为评价养禽场入场车辆消毒效率以及阐明消毒后细菌未灭活的原因,研究了常用消毒剂对入场车辆表面微生物的杀灭效果、消毒池内消毒剂存放时间对消毒效果的影响以及未灭活细菌对消毒剂的耐药情况,对消毒前后轮胎和车身表面的微生物进行监测,检测项目包括菌落总数、大肠菌群数、霉菌数、金黄色葡萄球菌数和沙门菌数,测定未杀灭细菌对消毒剂的最小杀菌浓度(MBC).结果显示:养禽场入场车辆消毒效果明显,通过消毒池和车辆消毒通道消毒后,轮胎和车身的微生物含量均显著下降;消毒池内消毒剂使用1d后消毒效果显著降低;未杀灭分离菌大部分对消毒剂耐药.结果提示:对养禽场入场车辆进行消毒很有必要,为保证消毒效果,入场车辆应预先彻底冲洗后再进行消毒,并且每天更换消毒剂,科学合理使用消毒剂.

为了解不同笼养模式肉鸡场养殖模式的优缺点,采用FA-3型气溶胶粒度分布采样器,对3种不同笼养模式肉鸡场(地面网养改建场A、标准化笼养鸡场X、地面平养改建场Z)空舍期消毒前和消毒后舍内空气中的细菌进行了采样,从样品测序结果、α多样性指数、β多样性、细菌群落结构和细菌聚类方面进行了细菌群落组成分析.结果 表明:变形菌门不论是在消毒前还是在消毒后均是优势菌群,相对丰度位于87.4％ ～99.3％;除A鸡场外,叶杆菌属消毒前后均是优势菌群;消毒效果最好的是X鸡场,其次是A鸡场,最后是Z鸡场.通过对不同笼养模式肉鸡场空舍期消毒前后细菌菌落组成的分析,为最佳笼养肉鸡场养殖模式的选择提供依据.

我国的肉鸡产业已经逐步走向集团化生产占主体的时代,根据《中国畜牧兽医统计》的数据, 2018年46.3％的出栏肉鸡来源于100000只以上的生产企业[1],规模化畜牧生产在经济效益和社会效益两方面均具有无可比拟的优势:首先,雄厚的资本在应对疫情等重大事件时能够确保资金保证;另外,标准化的管理规范和生产操作规范能够最大程度地减少疫情高风险事件的发生.

Bacterial community composition of different particle size of suspended particulates in weaning pig house was preliminary studied,by high-throughput sequencing.This study collected aerosol microbe in weaning pig house with 5 ％ of the male sheep blood-AGAR culture medium for sampling medium,using Andersen-level 6 impact type air microorganism sample collector.The collected aerosol microbe was trained after 24 hours to extract DNA and amplify of the V3-V4 viriable regions of 16S rDNA.Afterwords,we analyzed bacterial community composition of different particle size of suspension particles in weaning pig house,by iIIumina MiSeq high-throughput sequencing.We obtained 301 065 high quality series at all levels and identified 2 104 OTUs (operational taxonomical unit) based on the 97 ％ similarity rule;By alpha diversity analysis,flora richness from big to small,in turn,was 3_4s,3_2s,3_1s,3_6s,3_5s and 3_3s,respectively.Flora diversity was slightly different through the analysis of the different index,but the highest diversity was from 3_2s,3_5s,the lowest was from 3_3s;Flora composition was mainly composed of 4 phylum,40 species.The richness of Proteobacteria and Firmicutes were the highest.Total percentage of Acinetobacter,Comamonas,Staphylococcus and Myroides were higher than others.Flora similarity of 3_1s,3_5s,3_4s and 3_2s were high through the PCoA (principal component analysis) based on UniFrac analysis.Difference of flora structure between 3_6s,3_3s and the others was observed.The richness of bacterial flora which diameter of suspended particulate was between 2.1 and 3.3μm was the highest.Fourteen species of bacteria had been reported pathogenic to people and animals.Community structure was different at all levels,and difference of adjacent level was great.