Martin S W
Can J Comp Med. 1985 Jan;49(1):15-20.
A mail survey of feedlot owners was conducted to evaluate the efficacy of prophylactic antimicrobials, given in the water, or in the ration at preventing illness and/or death. One hundred and twenty-seven farmers from southwestern Ontario collaborated in the study. The percentage of calves requiring individual antimicrobial treatment, for any reason within 28 days of arrival was 22.6% (median 17.8%) and 0.6% (median 0.2%) died in that period. The use of medicated starter rations was not associated with either treatment or mortality rates until the effects of a number of other variables were controlled, analytically. Thereafter, the use of medicated feed was associated with a decrease in mortality rate, but was unrelated to morbidity rate. Overall, the use of medicated water was not associated with treatment or mortality rates. The use of sulphonamides was associated with decreased morbidity, but increased mortality rates. After controlling, analytically using multiple regression, the effects of other variables, the use of medicated water was associated with a significant increase in mortality rates. The other major factors which influenced mortality rates were the number of calves per group, the number of subgroups of calves in each group and whether the group contained cattle from different sources; all were related to increased mortality rates. During a two year period, more feedlot owners appeared to be using medicated rations as opposed to medicated water, as a means of providing antimicrobials to their newly arrived calves.
对饲养场主进行了一项邮件调查，以评估在水中或日粮中添加预防性抗菌药物对预防疾病和/或死亡的效果。安大略省西南部的127位农民参与了这项研究。到达后28天内，因任何原因需要接受个体抗菌治疗的犊牛比例为22.6%（中位数为17.8%），在此期间犊牛死亡率为0.6%（中位数为0.2%）。在对一些其他变量的影响进行分析控制之前，使用含药起始日粮与治疗率或死亡率均无关联。此后，使用含药饲料与死亡率降低有关，但与发病率无关。总体而言，使用加药饮水与治疗率或死亡率均无关联。使用磺胺类药物与发病率降低有关，但死亡率增加。在使用多元回归进行分析控制其他变量的影响后，使用加药饮水与死亡率显著增加有关。影响死亡率的其他主要因素包括每组犊牛数量、每组犊牛的亚组数量以及该组是否包含来自不同来源的牛；所有这些都与死亡率增加有关。在两年期间，更多的饲养场主似乎在使用含药日粮而非加药饮水，作为向新到的犊牛提供抗菌药物的一种方式。
