Vandehaar M J, Flakoll P J, Beitz D C, Nissen S
Department of Animal Science, Iowa State University, Ames 50011.
J Dairy Sci. 1988 Dec;71(12):3352-61. doi: 10.3168/jds.S0022-0302(88)79940-3.
To examine whether alpha-ketoisocaproate supplementation affects milk production, 10 goats were fed either 0 or 1.1% calcium-alpha-ketoisocaproate for 2 wk and 12 cows were fed either 0 or .75% Na alpha-ketoisocaproate for 3 wk. Supplementation with alpha-ketoisocaproate increased milk fat content, milk fat yield, and 4% FCM yield in cows by an average of 5, 10, and 8%, respectively, for the treatment period. In cows, response of milk fat yield to alpha-ketoisocaproate was 120 g during wk 1 of treatment but diminished to 55 g by wk 3. Milk yield and milk protein yield tended to be greater in cows fed alpha-ketoisocaproate, but milk production efficiency and body weight were not altered by treatment in either species. Supplementation with alpha-ketoisocaproate had no significant effect on fatty acid composition of milk but tended to increase the percentage of C10 and C12 fatty acids. In goats, supplementation with alpha-ketoisocaproate had no significant effect on milk production or composition, but trends toward increased milk fat and protein content were observed. Results indicate that alpha-ketoisocaproate acutely stimulates milk fat production in lactating cows and that this effect seems to diminish with time.
为研究补充α-酮异己酸是否会影响产奶量，10只山羊分别饲喂0或1.1%的α-酮异己酸钙，持续2周；12头奶牛分别饲喂0或0.75%的α-酮异己酸钠，持续3周。在治疗期内，补充α-酮异己酸使奶牛的乳脂含量、乳脂产量和4%乳脂校正乳产量平均分别提高了5%、10%和8%。在奶牛中，治疗第1周乳脂产量对α-酮异己酸的反应为120克，但到第3周降至55克。饲喂α-酮异己酸的奶牛产奶量和乳蛋白产量往往更高，但两种动物的治疗均未改变产奶效率和体重。补充α-酮异己酸对牛奶脂肪酸组成无显著影响，但倾向于增加C10和C12脂肪酸的百分比。在山羊中，补充α-酮异己酸对产奶量或组成无显著影响，但观察到乳脂和蛋白质含量有增加趋势。结果表明，α-酮异己酸能急性刺激泌乳奶牛的乳脂生成，且这种作用似乎会随时间减弱。
