Pre-weaning nutrition has significant influence on post-weaning performance of lambs. Strategic weaning management on milk replacer allowance at this phase can be a promising approach for harvesting desired carcass trait in finisher phase. Therefore, present experiment aimed economizing pre-weaning weight gain in lambs by feeding milk replacer and subsequently minimizing weaning age. A study of 90 days duration was conducted to determine the production performance, nutrient utilization and rumen fermentation of lambs on milk replacer allowance at different weaning age. Sixty-six Malpura lambs (10 days of age) were randomly divided into 3 equal groups. Lambs in control group were allowed conventional free suckling of dam up to 90 day of age, whereas lambs in the two treatment groups, that is W60 and W90 were offered milk replacer and weaned at 60 and 90 days, respectively. Lambs in all groups were offered ad-libitum creep mixture, Ziziphus nummularia leaves, Vigna unguiculata hay and fresh Ailanthus excelsa leaves. Overall weight gain was 12.7 per cent higher (p < 0.05) in W90 than control whereas in W60 group it was statistically comparable with both control and W90 groups. Overall average daily gain was 12.1 per cent higher (p < 0.05) in W90 group as compared to control. In case of nutrient digestibility, there was significant depression of dry matter (DM), organic matter (OM), crude protein (CP) and neutral detergent fibre (NDF) by 16.9, 17.2, 9.3 and 32.0 per cent in W60 than control; however, in W90, CP digestibility was higher (p < 0.05) than control and W60. Considering economic analysis, the net return obtained from W90 (90 days weaning plus milk replacer allowance) was more 20.0 per cent higher than control. Therefore, it can be concluded that lamb rearing on milk replacer and weaning at 90 days have a sustained positive effect on lambs’ production performance and is more profitable than the practice of milk replacer allowance and early weaning in semiarid conditions.

中文翻译：

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半干旱条件下不同断奶日龄马尔普拉羔羊的生长性能、瘤胃发酵及经济分析

断奶前营养对羔羊断奶后的生产性能有显着影响。在此阶段对代乳品津贴进行战略性断奶管理可能是在育肥阶段收获所需胴体性状的有前景的方法。因此，本实验旨在通过饲喂代乳品和随后最小化断奶年龄来节省羔羊断奶前的体重增加。一项为期 90 天的研究确定了不同断奶日龄羔羊的生产性能、养分利用和瘤胃发酵。将 66 只 Malpura 羔羊（10 日龄）随机分成 3 个相等的组。对照组的羔羊被允许常规自由哺乳至90日龄，而两个治疗组的羔羊，也就是说，W60 和 W90 分别在 60 天和 90 天提供代乳品并断奶。提供所有组的羔羊随意的蠕变混合物，Ziziphus nummularia叶子，Vigna unguiculata干草和新鲜的臭椿叶。W90 组的总体体重增加比对照组高 12.7%（p  < 0.05），而 W60 组与对照组和 W90 组在统计学上具有可比性。与对照组相比，W90 组的总体平均日增重高出 12.1%（p  < 0.05）。在养分消化率方面，W60 的干物质 (DM)、有机物 (OM)、粗蛋白 (CP) 和中性洗涤纤维 (NDF) 比对照显着下降 16.9%、17.2%、9.3% 和 32.0%；然而，在 W90 中，CP 消化率更高（p < 0.05) 比对照和 W60。考虑到经济分析，从 W90（断奶 90 天加上代乳品津贴）获得的净回报比对照高出 20.0% 以上。因此，可以得出结论，使用代乳粉饲养羔羊并在 90 天断奶对羔羊的生产性能具有持续的积极影响，并且比半干旱条件下的代乳粉津贴和早期断奶的做法更有利可图。