Physiological and behavioral changes of beef cattle after castration management

ABSTRACT The aim of this study was to evaluate the performance, physiological and temperamental parameters of uncastrated beef cattle or those submitted to surgical castration or immunocastration, in the post-castration period. The experimental period was divided into two subperiods of observations: the first 15 days post-castration (healing period) and the 25 days following healing. In the first 15 days of evaluation, the non-castrated animals obtained a greater average daily gain of weight in relation to surgically castrated. The heart rate was higher for surgically castrated animals with 126,51 beats/minute, compared to the other treatments. The distance of escape was higher for the surgically castrated steers, with a value of 12,22 meters, when compared to the other groups studied. During the next 25 days of surgical castration, the mean daily gain of weight was higher in surgically castrated cattle than in non-castrated or immunocastrated cattle. The escape velocity, in the second evaluation subperiod, was superior in the castrated cattle, in relation to the not castrated. The immediate castration period, the first 15 days, altered the mean daily gain and the total weight gain, the physiological and temperamental parameters of surgically castrated cattle, however, after the healing period, these differences diminish or disappear.

摘要 本研究旨在评估去势后时期内，未去势肉牛（beef cattle）、接受手术去势（surgical castration）或免疫去势（immunocastration）的肉牛的生产性能、生理及气质参数。实验周期划分为两个观测子阶段：去势后前15天（愈合期），以及愈合后的25天观测期。在首个15天评估期内，未去势动物的平均日增重（average daily gain）高于手术去势组。手术去势组动物的心率（heart rate）达126.51次/分钟，显著高于其余处理组。手术去势阉牛的逃逸距离（escape distance）为12.22米，同样高于其余受试组别。在手术去势后的后续25天观测期内，手术去势肉牛的平均日增重高于未去势或免疫去势肉牛。在第二个评估子阶段，去势肉牛的逃逸速度（escape velocity）高于未去势个体。去势初期（即前15天）会改变手术去势肉牛的平均日增重、总增重以及生理和气质参数，但在愈合期后，上述差异会逐渐减弱甚至消失。