König C D, Schippers R, van Egmond F J, Peters J W
Tijdschr Diergeneeskd. 1981 May 1;106(9):431-7.
The effect of treatment with clenbuterol on lambing during the period from 9 p.m. to 5 a.m. was studied in a field trial in sheep, which was continued for twenty-two days. The date of tupping was not known. The sheep were divided into an experimental and a control group, each numbering 106 animals. Animals of the experimental group were assessed every day at approximately 7.30 p.m., using a system of scoring for the development of udders and vulvae, and were treated with oral administration of 200 micrograms of clenbuterol when the findings suggested that parturition would occur that night. Seventy-nine animals of the experimental group lambed. twelve of them lambing during the night (two of these had been treated in the evening before lambing); of the group of controls, seventy-two lambed, twenty-three doing so during the night (difference significant: P greater than 0.05). The difference in the number of lambings during the night between treated and untreated animals was highly significant (P less than 0.001). Side-effects of clenbuterol were not recorded. The amount of clenbuterol used in the group of controls was: 3.49 tablets/lambing sheep, 5.03 tablets/treated sheep and 5.02 tables/treated and lambing sheep. This high consumption rate is attributed to the fact that the date of tupping was not known as well as to the defectiveness of the criteria on which the decision to treat or not to treat was based.
在一项持续22天的绵羊田间试验中，研究了在晚上9点至凌晨5点期间使用克伦特罗治疗对产羔的影响。配种日期未知。绵羊被分为实验组和对照组，每组106只动物。实验组的动物每天晚上7点30分左右进行评估，采用乳房和外阴发育评分系统，当评估结果表明当晚可能分娩时，对其口服200微克克伦特罗进行治疗。实验组中有79只母羊产羔，其中12只在夜间产羔（其中2只在产羔前一晚接受了治疗）；对照组中有72只母羊产羔，其中23只在夜间产羔（差异显著：P大于0.05）。治疗组和未治疗组在夜间产羔数量上的差异非常显著（P小于0.001）。未记录到克伦特罗的副作用。对照组中克伦特罗的用量为：每只产羔母羊3.49片，每只治疗母羊5.03片，每只治疗且产羔母羊5.02片。如此高的消耗率归因于配种日期未知以及治疗与否决策依据标准的缺陷。
