西藏农区犊牛死亡原因调查

为确认西藏农区黄牛、奶牛、犏牛和牦牛犊牛死亡率比例较高的原因,经实地走访调查、对发病牛、死亡牛剖检、采样于实验室进行病原学和血清学检测。结果表明,营养不良导致免疫力低下,使病原菌侵入并迅速繁殖,最终导致犊牛致死的主要原因。进一步的病原学和血清学检测结果表明,西藏农区犊牛病死率为9.34%,其中以昌都犊牛死亡率为最高达10.10%、拉萨市8.50%的犊牛死亡率为最低;西藏农区虚弱犊牛、发病犊牛、濒死犊牛血液、组织样本大肠埃希菌平均阳性率为48.05%,沙门菌平均阳性率为31.54%;濒死犊牛的血清经ELISA、凝集试验等方法检测口蹄疫、牛弓形体病等血清抗体水平均衡,均在98%以上。通过该调查研究,为防治西藏农区犊牛死亡提供了理论参考。

Investigation on Causative Factors of Calf Death in Tibet Agricultural Areas

In order to ascertain the causes of high mortality in calves in Tibetan agricultural areas,etiological and serological tests were carried out in the laboratory after field investigation and autopsy of diseased and dead cattle.Malnutrition resulted in low immunity of calves,which caused the invasion and rapid propagation of the pathogenic agents,and ultimately led to death.The etiological and serological tests showed that the fatality rate of calves in Tibetan agricultural areas was 9.34%.The highest and lowest mortality rate of calves were observed in Changdu and Lhasa,respectively,which were 10.10%and 8.50%,respectively.In the blood and tissue samples recovered from the weak,diseased and dying calves in Tibetan agricultural areas,the average positive rate of Escherichia coli and Salmonella was 48.05%and 31.54%,respectively.The serum antibody levels against some pathogenic agents of the dying calves were found higher than 98%by ELISA and agglutination test.This study provides theoretical references for control of the calf death in Tibetan agricultural areas.