Bandaranayaka D D, Holmes C W
Trop Anim Health Prod. 1976 Feb;8(1):38-46. doi: 10.1007/BF02383364.
Two pairs of Jersey cows were exposed to either 15 or 30 degrees C air temperature; intake of dried grass was controlled, to be equal at both temperatures. Exposure to 30 degrees C caused increases in rectal temperature and in respiratory rates, and decreases infood intakes in both cows. Milk yield decreased by similar amounts at both temperatures, in association with the decreases in food intakes. The fat and protein content of milk decreased significantly at 30 degrees C; the proportion of shorter chain fatty acids (C6-C14) IN THE milk fat also decreased at 30 degrees C. The proportion of acetic acid in the rumen contents decreased significantly at 30 degrees C, in association with a small decrease in pH. The results indicate that changes in the metabolism of cows occurred at 30 degrees C, independently of changes in food intake.
将两对泽西奶牛分别置于15摄氏度或30摄氏度的气温环境中；干草摄入量受到控制，使两个温度下的摄入量相等。暴露于30摄氏度环境中会导致奶牛直肠温度升高、呼吸频率增加，且采食量减少。两个温度下牛奶产量均下降了相似幅度，且与采食量减少相关。30摄氏度时牛奶的脂肪和蛋白质含量显著降低；30摄氏度时乳脂中短链脂肪酸（C6 - C14）的比例也降低。30摄氏度时瘤胃内容物中乙酸的比例显著降低，同时pH值略有下降。结果表明，奶牛代谢的变化在30摄氏度时就已发生，与采食量的变化无关。
