Reynolds L L, Brown D L
Dept. of Anim. Sci., University of California, Davis 95616.
J Anim Sci. 1991 Apr;69(4):1354-62. doi: 10.2527/1991.6941354x.
Two experiments were conducted to examine the milk producing ability of Western White-Faced sheep and to identify traits that correlate well with milk production. In Exp. 1, 31 Targhee ewes were milked and five samples were taken during 107-d lactations in which the ewes nursed twin lambs. Milk yield and composition, lamb weights, ewe weights, wool growth, and udder size also were measured. In Exp. 2, 24 ewes (Rambouillet x Finn-Dorset) were separated from their lambs at 7 wk and milked twice per day for eight more weeks, during which milk yield and composition, feed consumption, udder width, and ewe weights were measured. Results from Exp. 1 showed that lamb 30-d weights, ewe weights at breeding time, and udder width at peak lactation were highly correlated with suckled milk yield (r = .81, .75 and .66, respectively). Results from Exp. 2 indicated that lamb weights and ewe weights were not useful for predicting milk yield in dairy ewes, but feed intake and udder width were (r = .74 and .86, respectively). Single-day milk yield measurements were excellent estimators of total lactation yield in both experiments. Milk yields averaged 1,714 g/d in the suckled ewes and 477 g/d in the dairy ewes.
进行了两项试验，以检验西部白面羊的产奶能力，并确定与产奶量密切相关的性状。在试验1中，对31只塔基母羊进行挤奶，并在107天的泌乳期内采集了5次样本，在此期间母羊哺育双胞胎羔羊。还测量了产奶量和成分、羔羊体重、母羊体重、羊毛生长情况以及乳房大小。在试验2中，24只母羊（兰布耶羊×芬兰多塞特羊）在7周龄时与其羔羊分开，每天挤奶两次，持续8周，在此期间测量产奶量和成分、采食量、乳房宽度和母羊体重。试验1的结果表明，羔羊30日龄体重、配种时母羊体重以及泌乳高峰期乳房宽度与哺乳产奶量高度相关（相关系数分别为0.81、0.75和0.66）。试验2的结果表明，羔羊体重和母羊体重对于预测奶用母羊的产奶量并无用处，但采食量和乳房宽度则有用（相关系数分别为0.74和0.86）。在两项试验中，单日产奶量测量都是总泌乳量的优秀估计指标。哺乳母羊的平均产奶量为1714克/天，奶用母羊的平均产奶量为477克/天。
