Pedron O, Tedesco D, Giuliani G, Rizzi R
University of Milan, Italy.
J Dairy Sci. 1989 May;72(5):1286-90. doi: 10.3168/jds.S0022-0302(89)79234-1.
Effect of rump conformation on calving interval of 520 Italian Holstein Friesian heifers was evaluated with simultaneous adjustment for herd, year of birth, calving month, age at first parturition, and milk production. All factors, except age at first parturition, were important sources of variation. Heifers with narrow rumps at the pins had the longest calving interval. There were significant differences among the herds. Cows born between 1979 and 1981 had shorter calving intervals, probably resulting from a national plan against bovine infertility initiated in 1981. Cows calving in July had better reproductive performance. There was positive relationship between milk production and calving interval.
对520头意大利荷斯坦弗里生小母牛的臀部形态对产犊间隔的影响进行了评估，并同时对牛群、出生年份、产犊月份、初产年龄和产奶量进行了调整。除初产年龄外，所有因素都是重要的变异来源。臀部狭窄的小母牛产犊间隔最长。不同牛群之间存在显著差异。1979年至1981年出生的母牛产犊间隔较短，这可能是由于1981年启动的一项全国性抗牛不育计划。7月份产犊的母牛繁殖性能更好。产奶量与产犊间隔之间存在正相关关系。
