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):565-74. doi: 10.3168/jds.S0022-0302(96)76401-9.
The effects particle size of corn grain and the ionophore lasalocid on ruminal fermentation and feeding behavior of early lactation cows were examined. 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. Ground corn decreased ruminal turnover time of starch, did not affect ruminal lactate concentrations, increased propionate, decreased the ratio of acetate to propionate, and decreased branched-chain fatty acids. The range of ruminal pH within a day increased with ground corn, but mean pH was unaffected by treatment. Lasalocid increased lactate concentrations and did not affect the ratio of acetate to propionate. Lasalocid increased total time spent ruminating, and ground corn decreased ruminal contractions. Lasalocid tended to increase water intake, and ground corn increased water intake. Interactions of lasalocid and particle size of the corn grain were observed for ruminal turnover time of starch and NDF, and ruminal pool size of acetate and total VFA.
研究了玉米粒粒度和离子载体拉沙洛西对初产奶牛瘤胃发酵和采食行为的影响。选用8头经产和4头初产的初产奶牛，给它们饲喂含有破碎或粉碎的干脱壳玉米粒且添加或不添加拉沙洛西（每头奶牛每天360毫克）的日粮（44%为粗饲料）。试验采用重复（n = 3）的4×4拉丁方设计，每期21天，处理采用2×2析因安排。粉碎玉米降低了淀粉在瘤胃中的周转时间，不影响瘤胃乳酸浓度，增加了丙酸含量，降低了乙酸与丙酸的比例，并降低了支链脂肪酸含量。一天内瘤胃pH值的范围随粉碎玉米而增加，但平均pH值不受处理影响。拉沙洛西增加了乳酸浓度，不影响乙酸与丙酸的比例。拉沙洛西增加了反刍总时间，粉碎玉米减少了瘤胃收缩。拉沙洛西倾向于增加饮水量，粉碎玉米也增加了饮水量。在淀粉和中性洗涤纤维的瘤胃周转时间以及乙酸和总挥发性脂肪酸的瘤胃池大小方面，观察到拉沙洛西与玉米粒粒度之间存在相互作用。
