Spicer L J, Vernon R K, Tucker W B, Wettemann R P, Hogue J F, Adams G D
Department of Animal Science, Oklahoma State University, Stillwater 74078.
J Dairy Sci. 1993 Sep;76(9):2664-73. doi: 10.3168/jds.S0022-0302(93)77602-X.
The objective was to determine the effects of dietary inert fat on estimated energy balance, hormones in plasma, and reproduction during early lactation. From wk 0 to 12 postpartum, 14 pluriparous Holstein cows were fed individually a TMR, and blood samples were taken twice weekly for quantification of IGF-I, progesterone, and cholesterol. During wk 5 to 12, one-half of the cows remained on the TMR, and the other half were fed the TMR containing inert fat at 1.8% of dietary DM. Estrous behavior was monitored twice daily, and body condition scores were recorded every 4 wk. Cows fed inert fat between wk 5 and 12 postpartum had similar concentrations of IGF-I in plasma but greater luteal phase progesterone secretions than cows fed the control diet. Total cholesterol in plasma also was greater in cows fed inert fat than in cows fed the control diet. Intervals to first, second, and third ovulation or estrus did not differ among cows fed control or inert fat diets. Body condition scores, daily DMI, and milk production were not affected by dietary inert fat. Inert fat fed to cows between wk 5 and 12 postpartum did not affect ovulatory activity but may enhance luteal activity.
本研究旨在确定日粮中添加惰性脂肪对泌乳早期能量平衡估算值、血浆激素水平及繁殖性能的影响。从产后第0周开始至第12周，14头经产荷斯坦奶牛分别单独饲喂全混合日粮（TMR），每周采集两次血样，用于测定胰岛素样生长因子-I（IGF-I）、孕酮和胆固醇含量。在第5周第12周期间，一半奶牛继续饲喂TMR，另一半奶牛则饲喂含1.8%日粮干物质的惰性脂肪TMR。每天监测发情行为两次，每4周记录一次体况评分。产后第5周第12周期间饲喂惰性脂肪的奶牛血浆中IGF-I浓度相近，但黄体期孕酮分泌量高于饲喂对照日粮的奶牛。饲喂惰性脂肪奶牛的血浆总胆固醇含量也高于饲喂对照日粮的奶牛。饲喂对照或含惰性脂肪日粮的奶牛，首次、第二次和第三次排卵或发情的间隔时间无差异。体况评分、每日干物质采食量和产奶量不受日粮中惰性脂肪的影响。产后第5周~第12周期间给奶牛饲喂惰性脂肪不影响排卵活动，但可能会增强黄体功能。
