日粮蛋白质和淀粉水平对肉牛日粮淀粉瘤胃发酵和小肠表观消化的影响

摘要:为了研究日粮蛋白质和淀粉水平对肉牛日粮淀粉瘤胃发酵和小肠消化的影响，试验选择体重650 kg 左右，安装有瘤胃、真胃瘘管的荷斯坦（Holstein）公牛4 头，按4×4拉丁方实验设计分别饲喂精粗比和进食量相同的4 种蛋白质和淀粉水平日粮，以三氧化二铬（Cr2O3）作真胃食糜标记物，全收粪法收集粪样，测定真胃食糜和粪便中的淀粉流量及在瘤胃内、真胃后段消化道（简称肠道）内的表观消化率。结果表明日粮蛋白质和淀粉水平对瘤胃淀粉发酵率和全消化道的淀粉表观消化率没有显著影响(p>0.05)，瘤胃淀粉发酵率和全消化道淀粉的表观消化率分别为83.5%和97.4%，日粮淀粉水平明显影响瘤胃发酵和小肠消化的淀粉量(p<0.05)，并随淀粉进食量减少而下降(p<0.05)。

Effects of Varying Protein and Starch in the High-Concentrate Diet of Steers on Ruminal Fermentation and Intestinal Digestion of Starch

Abstract The main objective of this experiment was to determine the effects of the amount of CP and starch in the diet of steers on ruminal fermentation, passage of starch to the small intestine, and starch digestibility. For this purpose, 4 Holstein steers fistulated in the rumen and abomasum were used in a 4×4 Latin square design at four treatments. With four level of CP and two level of starch in the diet. On an air-dry matter basis, diets contained 25% hay, 25% alfalfa and 50% concentrate. Digestibilities in the rumen and total tract of starch were unaffected by increasing the dietary CP or decreasing the starch of diet (p>0.05), The percentage of starch apparently digested in the rumen and total tract were 83.5% and 97.4%, respectively. Increasing dietary CP or decreasing dietary starch decreased the ruminal outflow, apparent ruminal and total tract digestion of starch (p<0.05). Results of this study suggest that decreased the proportion of starch consumed by the steers that was apparently digested in the small intestine. the amount of starch in the diet of steers on starch passage to the small intestine.