Knowlton K F, Allen M S, Erickson P S
Department of Animal Science, Michigan State University, East Lansing 48824-1225, USA.
J Dairy Sci. 1996 Apr;79(4):557-64. doi: 10.3168/jds.S0022-0302(96)76400-7.
The effects were examined of corn grain particle size and the ionophore lasalocid on performance, blood parameters, and nutrient digestibility of early lactation cows. Smaller corn particle size was expected to result in faster rate of digestion and ruminal fermentation of starch. Eight multiparous and 4 primiparous cows in early lactation were fed diets (44% forage) with cracked or ground, dried shelled corn grain and with or without lasalocid (360.mg/d per cow). The experiment was a replicated (n = 3) 4 x 4 Latin square design with 21-d periods and a 2 x 2 factorial arrangement of treatments. Lasalocid tended to improve DMI. Lasalocid and ground corn decreased body condition loss and milk fat and increased milk protein. Ground corn tended to increase milk yield but had no effect on 4% FCM, lactose, and BW. For all cows, milk yield, 4% FCM, lactose, and BW were unaffected by lasalocid; however, subsequent analysis of individual squares revealed that milk yield of primiparous cows increased with lasalocid. Ground corn increased total tract starch digestibility and decreased NDF digestibility. Interactions between lasalocid and particle size of corn grain were observed only for change in serum insulin concentration before and after meals.
研究了玉米粒度和离子载体拉沙洛西对初产奶牛生产性能、血液参数和养分消化率的影响。预计较小的玉米粒度会使淀粉的消化速度和瘤胃发酵速度加快。给8头经产和4头初产的初产奶牛饲喂含破碎或磨碎的干脱壳玉米粒且添加或不添加拉沙洛西（每头奶牛每日360毫克）的日粮（44%为粗饲料）。试验采用重复（n = 3）4×4拉丁方设计，每期21天，处理采用2×2析因安排。拉沙洛西倾向于提高干物质采食量。拉沙洛西和磨碎的玉米减少了体况损失和乳脂，并增加了乳蛋白。磨碎的玉米倾向于提高产奶量，但对4%乳脂校正乳、乳糖和体重没有影响。对于所有奶牛，产奶量、4%乳脂校正乳、乳糖和体重不受拉沙洛西影响；然而，随后对各个方区的分析表明，初产奶牛的产奶量随拉沙洛西增加。磨碎的玉米提高了全消化道淀粉消化率，降低了中性洗涤纤维消化率。仅在餐前后血清胰岛素浓度变化方面观察到拉沙洛西与玉米粒粒度之间的相互作用。
