Alexander B H, MacVean D W, Salman M D
Department of Environmental Health, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins 80523.
J Am Vet Med Assoc. 1989 Jul 15;195(2):207-11.
Using data collected from company lot records, potential risk factors related to feedlot management, the cattle, and climate were determined. The risk factors were analyzed by use of weighted multiple regression techniques to determine their effects on the incidence of lower respiratory tract disease in a cohort of 95 lots containing 17,696 cattle. The gender of the cattle, the number of days that groups of cattle filled a lot, pregnancy checking of heifers, and the average temperature change in the first 14 days in which the cattle were on feed significantly influenced the incidence of lower respiratory disease. The incidence of lower respiratory tract disease was most influenced by risk factors in the first 30 days on feed.
利用从公司批次记录中收集的数据，确定了与饲养场管理、牛群以及气候相关的潜在风险因素。运用加权多元回归技术对这些风险因素进行分析，以确定它们对95个批次、共17696头牛的下呼吸道疾病发病率的影响。牛的性别、牛群在一个批次中存栏的天数、小母牛的妊娠检查以及牛开始采食后的前14天的平均温度变化，对下呼吸道疾病的发病率有显著影响。下呼吸道疾病的发病率受采食后前30天风险因素的影响最大。
