Vasseur E, Rushen J, de Passillé A M
Animal Sciences Department, Laval University, Quebec, Quebec, Canada.
J Dairy Sci. 2009 Aug;92(8):3915-21. doi: 10.3168/jds.2008-1823.
Dairy producers often complain that calves have difficulty consuming the recommended amount of colostrum. A better understanding of factors affecting calves' motivation to ingest colostrum could help develop better management. Thirty-six Holstein calves were tested to evaluate effects of time since birth (2 vs. 6 h) and provision of a heat lamp on motivation to ingest colostrum in a 2 x 2 factorial model. Calves were randomly assigned to treatments balancing for birth weight and sex. Calves were provided colostrum (>68 g of Ig/L) ad libitum from a teat-bottle. We tested the calf's suckling reflex by examining the response to orofacial stimulation and assessed the calf's vigor from the duration of time spent standing or attempting to stand in the hour after birth and standing during colostrum feeding. During the first meal, 42% of calves consumed 4 L or more of colostrum, 25% consumed 3 to 4 L, 11% consumed 2 to 3 L, and 22% consumed <2 L. There were no significant effects of heat supply or time since birth on consumption. The quantity of colostrum ingested was best predicted (r(2) = 0.61) by a combination of birth weight, vigor during colostrum feeding, and vigor during the first hour of life, whereas meal duration was predicted (r(2) = 0.34) jointly by room temperature and having suckled the dam. Colostrum intake was lower for small calves and calves with a low degree of vigor. Differences among calves in the strength of the sucking reflex were not related to colostrum intake.
奶农们常常抱怨犊牛难以摄入推荐量的初乳。更好地了解影响犊牛摄入初乳积极性的因素有助于改进管理措施。采用2×2析因模型，对36头荷斯坦犊牛进行了测试，以评估出生后时间（2小时与6小时）和提供加热灯对其摄入初乳积极性的影响。犊牛根据出生体重和性别随机分配到各处理组。通过奶瓶随意给犊牛提供初乳（免疫球蛋白含量>68 g/L）。我们通过检查犊牛对口面部刺激的反应来测试其吸吮反射，并根据犊牛出生后1小时内站立或试图站立的时长以及初乳喂养期间站立的时长来评估其活力。在第一餐时，42%的犊牛摄入了4升或更多的初乳，25%的犊牛摄入了3至4升，11%的犊牛摄入了2至3升，22%的犊牛摄入了不到2升。供热或出生后时间对初乳摄入量没有显著影响。初乳摄入量最好由出生体重、初乳喂养期间的活力以及出生后第一小时的活力综合预测（r² = 0.61），而喂奶持续时间则由室温以及是否吸吮过母牛共同预测（r² = 0.34）。小型犊牛和活力较低的犊牛初乳摄入量较低。犊牛吸吮反射强度的差异与初乳摄入量无关。
