Ostrowski S R, Smith B P, Spier S J, Norman B B, Oliver M N
Veterinary Medical Teaching Hospital, University of California, Davis 95616.
J Am Vet Med Assoc. 1989 Aug 15;195(4):481-4.
Cattle that had recovered from clinical oak bud toxicosis (as assessed by normal BUN and serum creatinine values and good appetite) performed better than did clinically normal herdmates when weight gain and feed efficiency were compared. Both groups had a rate of weight gain (oak bud-exposed cattle, 1.76 kg/steer/d; control cattle, 1.57 kg/steer/d) that exceeded the feedlot mean value (approximately 1.4 kg/d) for cattle (of similar starting weight and diet) that had zeranol implants, and the difference was significant (P less than 0.005) for both groups. The difference in weight gain performance of oak bud-exposed cattle, compared with control cattle, was not highly significant; however, the improved feed efficiency was significantly (P less than 0.05) better than that in controls (2.57 kg of feed/kg of weight gain vs 3 kg of feed/kg of weight gain). On the basis of accepted criteria (increased rate of weight gain and efficiency of feed conversion), the group of oak bud-exposed cattle of this study had compensatory weight gain. Thus, cattle with good evidence of clinical recovery from oak bud toxicosis can be expected to perform in the feedlot at least as well as cattle not exposed to oak bud toxicosis, and may have compensatory weight gain.
从临床橡树芽中毒中恢复过来的牛(通过正常的血尿素氮和血清肌酐值以及良好的食欲来评估)在比较体重增加和饲料效率时,表现优于临床正常的同群牛。两组牛的体重增加率(接触橡树芽的牛,1.76千克/头/天;对照牛,1.57千克/头/天)均超过了(起始体重和饮食相似)植入玉米赤霉醇的育肥牛场牛的平均值(约1.4千克/天),且两组差异均显著(P小于0.005)。与对照牛相比,接触橡树芽的牛在体重增加性能方面的差异并不十分显著;然而,其提高的饲料效率显著(P小于0.05)优于对照牛(每增重1千克所需饲料量为2.57千克对3千克)。根据公认标准(体重增加率提高和饲料转化率提高),本研究中接触橡树芽的牛群有补偿性体重增加。因此,可以预期,从橡树芽中毒中临床恢复良好的牛在育肥牛场中的表现至少与未接触橡树芽中毒的牛一样好,并且可能有补偿性体重增加。