Fuertes J A, Gonzalo C, Carriedo J A, San Primitivo F
Departamento de Producción Animal, Facultad de Veterinaria, Universidad de León, Spain.
J Dairy Sci. 1998 May;81(5):1300-7. doi: 10.3168/jds.S0022-0302(98)75692-9.
A total of 3119 test day records for milk yield, somatic cell count (SCC), and contents of fat, protein, casein, serum protein, lactose, and total solids were obtained weekly from 155 lactations of Churra ewes during both the suckling and milking periods. All of the variables were significantly affected by stage of lactation, number of live lambs weaned, age at parity, and parity number within age. The lactation curves for SCC and for percentages of protein, casein, fat, and total solids were related inversely to the lactation curves for milk yield and lactose percentage. The SCC curve reached its lowest point at wk 5, which coincided with the maximum milk yield. At wk 3, lactose content reached its peak, and contents of fat, protein, casein, and total solids reached their lowest points. After weaning, monthly within-lactation correlations of the variables were simulated; values were 0.584 for yield, 0.468 for SCC, 0.371 for casein percentage, 0.360 for total solids percentage, 0.350 for protein percentage, 0.342 for fat percentage, 0.270 for lactose percentage, and 0.030 for serum protein percentage. Simplified procedures based on only one milking (a.m. or p.m.) could be effective in the testing programs for milk yield and SCC, thus, reducing the economic costs of milk recordings in mammary health and breeding programs.
在哺乳和挤奶期间，每周从155头丘拉母羊的泌乳期获取总共3119条关于产奶量、体细胞计数（SCC）以及脂肪、蛋白质、酪蛋白、血清蛋白、乳糖和总固体含量的测试日记录。所有变量均受到泌乳阶段、断奶活羔羊数量、产次年龄和年龄内产次的显著影响。SCC以及蛋白质、酪蛋白、脂肪和总固体百分比的泌乳曲线与产奶量和乳糖百分比的泌乳曲线呈负相关。SCC曲线在第5周达到最低点，这与最高产奶量相吻合。在第3周，乳糖含量达到峰值，脂肪、蛋白质、酪蛋白和总固体含量达到最低点。断奶后，模拟了变量在泌乳期内的月度相关性；产奶量的值为0.584，SCC为0.468，酪蛋白百分比为0.371，总固体百分比为0.360，蛋白质百分比为0.350，脂肪百分比为0.342，乳糖百分比为0.270，血清蛋白百分比为0.030。基于仅一次挤奶（上午或下午）的简化程序在产奶量和SCC的测试项目中可能有效，从而降低乳腺健康和育种项目中牛奶记录的经济成本。
