Effects of feeding levels of a milk replacer on digestion and metabolism of nutrients, and serum biochemical indexes in lambs | 早期断奶羔羊代乳粉饲喂水平对营养物质消化代谢及血清生化指标的影响

中国人. 目的研究代乳粉饲喂水平对早期断奶羔羊生长发育、营养物质消化代谢及血清生化指标的影响。方法27只新生陶赛特（♂）×小尾寒羊（♀）杂交F1代羔羊随机分为低（L）、中（M）、高（H）3个饲喂水平组，分别按体重的1.0%、1.5%和2.0%饲喂代乳粉。羔羊于50―60、80―90日龄期间分别进行一期消化代谢试验，并在50、90日龄采集血液样品，分析血清生化指标。结果羔羊的体重（BW）和体尺（BL）随代乳粉饲喂水平的升高而增加，低、中、高3个处理组间的BW和BL差异显著（P＜0.05）。干物质（DM）、有机物（OM）、总能（GE）、氮（N）、粗脂肪（EE）、Ca、P消化率随饲喂水平的升高而升高，低饲喂水平组DM、GE、N、EE、Ca、P的消化率显著低于高饲喂水平组（P＜0.05），但在85―90日龄时，高饲喂水平组的N沉积率最低，仅为70.9%，显著低于低饲喂水平组的78.7%（P＜0.05）。50日龄时，各处理间的总蛋白（TP）、尿素氮（BUN）、血糖（GLU）、胆固醇CHOL、甘油三酯（TG）差异不显著（P＞0.05），但低、中饲喂水平组碱性磷酸酶（ALP）活性显著低于高饲喂水平组（P＜0.05）。90日龄时，高饲喂水平组CHOL显著高于低饲喂水平组（P＜0.05）。结论适宜代乳粉饲喂水平可显著提高羔羊生长性能及其对营养物质的消化率，改善饲料转化率（FCR）。20―50、50―70和70―90日龄羔羊的代乳粉饲喂水平分别按体重2.0%、1.5%和1.0%为宜。

英语. ObjectiveThis study was performed to investigate the effects of different feeding levels of a milk replacer on growth performance, nutrient digestion and metabolism, and serum biochemical parameters in early weaned lambs. MethodTwenty seven newborn crossbred F1 lambs (Dorset×Thin-Tailed Han sheep) were randomly divided into 3 groups and each fed with a milk replacer at 1.0% (L), 1.5% (M) or 2.0% (H) of BW. Digestion and metabolism trials were carried out from 50 to 60 and from 80 to 90 d of age, respectively. Blood metabolites were determined at 50 and 90 d of age. Result The growth performance of lambs was improved as the feeding levels of the milk replacer increased, significant differences in the BW and BL existed among three treatments (P＜0.05). As feeding levels increased, the digestibility of DM, OM, GE, N, EE, Ca and P rose. The digestibility of DM, GE, N, EE, Ca and P in the L group was significantly lower than that in the H group (P＜0.05), but the retention of N in the H group was only 70.9%, which was significantly lower than that in the L group (78.7%) (P＜0.05). At 50 d of age, no significant differences in the serum concentration of TP, BUN, GLU, CHOL and TG were detected among the groups(P＞0.05), but the activity of serum ALP in lambs from the L or M group was significantly lower than that from the H group (P＜0.05). At 90 d of age, the serum concentration of CHOL in the H group was significantly higher than that in the L group (P＜0.05). Conclusion A proper feeding level of milk replacers significantly improved the growth performance, and nutrient digestion and metabolism. The lambs of 20-50, 50-70 and 70-90 d of age were suggested to be fed at 2.0%, 1.5% and 1.0% BW, respectively.