Impact of foot-and-mouth disease on mastitis and culling on a large-scale dairy farm in Kenya

Foot and mouth disease (FMD) is a highly transmissible viral infection of cloven hooved animals associated with severe economic losses when introduced into FMD-free countries. Information on the impact of the disease in FMDV-endemic countries is poorly characterised yet essential for the prioritisation of scarce resources for disease control programmes. A FMD (virus serotype SAT2) outbreak on a large-scale dairy farm in Nakuru County, Kenya provided an opportunity to evaluate the impact of FMD on clinical mastitis and culling rate. A cohort approach followed animals over a 12-month period after the commencement of the outbreak. For culling, all animals were included; for mastitis, those over 18 months of age. FMD was recorded in 400/644 cattle over a 29-day period. During the follow-up period 76 animals were culled or died whilst in the over 18 month old cohort 63 developed clinical mastitis. Hazard ratios (HR) were generated using Cox regression accounting for non-proportional hazards by inclusion of time-varying effects. Univariable analysis showed FMD cases were culled sooner but there was no effect on clinical mastitis. After adjusting for possible confounders and inclusion of time-varying effects there was weak evidence to support an effect of FMD on culling (HR = 1.7, 95% confidence intervals [CI] 0.88-3.1, P = 0.12). For mastitis, there was stronger evidence of an increased rate in the first month after the onset of the outbreak (HR = 2.9, 95%CI 0.97-8.9, P = 0.057).

Electronic supplementary material

The online version of this article (doi:10.1186/s13567-015-0173-4) contains supplementary material, which is available to authorized users.     

PAL材料对育肥猪增重及肉品微量元素营养成分的影响

试验设4个组,即对照4组和试验1、2、3组,对照4组饲喂基础日粮,试验1、2、3组在基础日粮中添加1%、2%和4%PAL材料,试验猪经过育肥期饲养,试验结果表明,试验1、2、3组日增重分别高于对照4组62.41、19.79和19.79g;经肉品微量元素分析,试验组碘和锌含量明显高于对照组,其中试验1组、2组、3组碘含量水平分别比对照4组提高85.2、71.9和52.1μg/kg,有毒有害微量元素砷、汞、镉含量试验组与对照组接近。     

天祝白牦牛保种繁育体系构架与运行

为加强本种的保护与选育提高,逐步构架建立以"一场三区一站"为核心的开放保种繁育体系,经对该体系运行二十多年的保种选育资料分析, 截止2006年,保种区存栏天祝白牦牛3.94万头,占牦牛的44%,比体系建立初的1987年增加16个百分点.其中:核心群增加10群560头,选育群增加64群3 300头,一、二级牛比例分别增加14、16个百分点,白色被毛比例增加4个百分点.主要体尺、体重与生产性能,成年公牛平均体高、胸围和体重分别增加4.11 cm、15.37 cm和13.05 kg;成年公、母牛平均产毛绒、产肉量提高0.28 kg和 5.58 kg.体系构架、建立符合保种区实际,技术路线先进、合理,运行效果显著.     

引入肉羊品种与湖羊杂交的屠宰性能、肉品质及血液生化指标比较研究

旨在研究引入外来品种与湖羊杂交后对湖羊屠宰性能、肉品质及血液生化指标的影响。试验采用单因子试验设计,分为AH组(澳湖杂交F1代)、DH组(杜湖杂交F1代)和H组(纯繁湖羊对照组)3组,每组分别选取4月龄体重相近、体况良好的公羊3只、母羊2只。结果表明,在屠宰性能上,AH组和DH组的内脏脂肪占胴体重百分比、眼肌面积均显著高于H组(P<0.05),H组比高于AH组与DH组骨肉显著低于H组(P<0.05),DH组胴体脂肪含量值显著高于H组(P<0.05)。在肉品质上,肌肉剪切力DH组与AH组显著低于H组(P<0.05),AH组与DH组肌肉水分含量显著高于H组(P<0.05),DH组肌肉脂肪含量显著高于H组(P<0.05)。血液生化指标显示,AH组和DH组的球蛋白、谷草转氨酶及乳酸脱氢酶含量均显著高于H组(P<0.05)。综上,引入的2个绵羊品种与湖羊杂交,不仅可以提高湖羊屠宰性能及肉用品质,还可以有效地改善湖羊血液生化指标。     

PAL材料对育肥猪增重及肉品微量元素营养成分的影响

试验设4个组(对照Ⅳ组和试验Ⅰ、Ⅱ、Ⅲ组),对照Ⅳ组饲喂基础日粮,试验Ⅰ、Ⅱ、Ⅲ组在饲喂基础日粮的基础上按基础日粮的1%、2%和4%添加PAL材料。试验猪经过一个育肥期饲养,结果表明:试验Ⅰ、Ⅱ、Ⅲ组日增重分别高于对照Ⅳ组62.41g、19.79g和19.79g;经肉品微量元素分析,试验组瘦肉率高于对照组0.69%～4.02%,碘、锌含量明显增加,其中试验Ⅰ组、Ⅱ组、Ⅲ组碘含量水平(按100g肉中含量计)分别比对照Ⅳ组提高8.52μg、7.19μg和5.21μg,有毒有害微量元素砷、汞、镉含量试验组与对照组接近,铅含量水平由对照组的0.069μg/kg降为试验组的0.023μg/kg。     

A retrospective study of Newcastle disease in Kenya

Tropical Animal Health and Production - Newcastle disease (ND) is a major constraint to Kenya’s poultry production, which is comprised of approximately 80% indigenous chickens (ICs; caged and...