抗应激处理对肉牛引入后发病的影响

Effect on on Disease Occurrence of Heifers After Arrival at Feedlots by Anti Stress Treatment

[目的]旨在探讨肉牛启运前进行抗应激处理对降低肉牛引入后发病的效果。[方法]对两批共99头牛分别进行启运前注射牛支原体灭活疫苗（第一批）与盐酸氯丙嗪（第二批）,途中运输时间分别为36 h与48 h,运输途中不给食物与饮水。牛运抵后继续观察35 d,记录发病情况。[结果]两批对照牛的平均发病率为67%。小体重组（250－300 kg）牛的发病率显著高于大体重组（300－350 kg组和350－400 kg组）发病率（P〈0.05）。虽然接种疫苗诱导产生了抗体,但接种应激加重了牛引入后发病。牛运输前肌注盐酸氯丙嗪组较对照组发病率显著降低（P〈0.05）,且0.6 mg/kg比0.3 mg/kg效果更好（P〈0.05）。[结论]启运前采用肌注盐酸氯丙嗪的抗应激处理能显著降低牛引入后的发病率。

【Objective】This study was aimed to explore the effect of anti stress treatment on disease occurrence of the heifers after arrival at feedlots.【Method】Two batches of 99 heifers were injected bovine mycoplasma inactivated vaccine（the first batch） and Chlorpromazine Hydrochloride（the second batch）,respectively.The transportation time was 36 h and 48 h for the two batches,respectively.During the transportation,no water and feed were provided to the heifers.After arriving,the heifers continued the observation of 35 days.Then the disease occurrence was recorded.【Result】The overall average incidence for the two groups was 67%.The low bodyweight group（250～300 kg） had a apparently higher incidence（90%） than that of high bodyweight group（300～350 kg and 350～400 kg）.Although the vaccination before the transportation induced the antibody production,the inoculation stress exacerbated the disease occurrence.However,the Chlorpromazine Hydrochloride injection group significantly decreased the incidence.Furthermore the group with 0.6mg/kg dosage exerted better efficacy than that of 0.3 mg/kg group.【Conclusion】the antistress treatment with Chlorpromazine Hydrochloride injection before transportation could significantly decrease the disease incidence of heifers after arrival at feedlots.