Institute of Animal Nutrition and Feed Technology, University of Agriculture, Faisalabad, Pakistan.
Animal. 2012 Aug;6(8):1231-6. doi: 10.1017/S1751731112000250.
The objective of the study was to assess the post-weaning growth response of Sahiwal calves reared on four different pre-weaning dietary regimens. The four diets were: (a) whole cow's milk, starter ration (SR; CP = 20%, total digestible nutrients (TDN) = 72%) and Berseem hay (H; Egyptian clover; CP = 21%, TDN = 63%); (b) whole cow's milk + H; (c) milk replacer (MR; reconstituted to supplier specification; Sprayfo®) + SR + H; and (d) MR + H. The protein and fat percentages of reconstituted MR were 2.22 and 1.84, respectively. Milk or MR were fed at the rate of 10% of the calves' body weight (BW) until 56 days of age, and then withdrawn gradually until weaned completely by 84 days of age. The average initial BW of calves in groups A, B, C and D were 56.3 ± 1.0, 47.5 ± 1.0, 40.4 ± 1.0 and 30.3 ± 1.0 kg, respectively. Initially, there were 12 calves in each group with six of each sex; however, one male calf died from each of groups B and C and were not replaced. During the post-weaning period, 13 to 24 weeks, the calves were fed a single total mixed ration ad libitum based on maize, canola meal, wheat straw and molasses containing 16% CP and 70% TDN. Daily feed intake and weekly BW gains were recorded. The data were analyzed by MIXED model analysis procedures using the statistical program SAS. The intake of calves as percent of their BW, feed conversion ratio and cost per kg of BW gain were not different (P > 0.05) across treatments. The daily gain at 24 weeks of age for the pre-weaning treatments A, B, C and D were 746 ± 33, 660 ± 33, 654 ± 33 and 527 ± 33 g/day and the final liveweights of calves were 119 ± 4.2, 102 ± 4.2, 95 ± 4.2 and 75 ± 4.2 kg, respectively. Gains were influenced significantly (P < 0.05) by pre-weaning treatments. The calves fed MR and H only during the pre-weaning period were unable to catch up post weaning with calves on other dietary treatments. The calves fed whole milk from birth at the rate of 10% of liveweight together with concentrates had higher weaning weight and superior growth rate post weaning as well. Thus, pre-weaning feeding was important for higher weaning weights and superior growth rates post weaning.
本研究旨在评估在四种不同预断奶日粮下饲养的萨希瓦尔犊牛的断奶后生长反应。这四种日粮分别为：（a）全牛奶、开食料（CP=20%，总可消化养分（TDN）=72%）和 Berseem 干草（埃及三叶草；CP=21%，TDN=63%）；（b）全牛奶+Berseem 干草；（c）牛奶替代品（MR；按供应商规格配制；Sprayfo®）+开食料+Berseem 干草；和（d）MR+Berseem 干草。再制 MR 的蛋白质和脂肪百分比分别为 2.22%和 1.84%。牛奶或 MR 以犊牛体重的 10%的速度喂养，直到 56 日龄，然后逐渐减少，直到 84 日龄完全断奶。A、B、C 和 D 组犊牛的平均初始体重分别为 56.3±1.0、47.5±1.0、40.4±1.0 和 30.3±1.0 千克。最初，每个组有 12 头犊牛，每性别 6 头，但 B 组和 C 组各有一头雄性犊牛死亡，没有替补。在断奶后 13 至 24 周期间，犊牛自由采食以玉米、菜籽油饼、小麦秸秆和糖蜜为基础的单一全混合日粮，日粮含有 16%的 CP 和 70%的 TDN。记录每日采食量和每周体重增加。数据采用统计程序 SAS 的 MIXED 模型分析程序进行分析。在处理之间，犊牛的采食量占体重的百分比、饲料转化率和每公斤体重增加的成本没有差异（P>0.05）。预断奶处理 A、B、C 和 D 的 24 周龄日增重分别为 746±33、660±33、654±33 和 527±33 g/天，犊牛的最终活重分别为 119±4.2、102±4.2、95±4.2 和 75±4.2 kg。预断奶处理对增重有显著影响（P<0.05）。仅在预断奶期间用 MR 和 H 喂养的犊牛在断奶后无法赶上其他日粮处理的犊牛。从出生开始，以活体重的 10%的速度用全牛奶喂养并配合浓缩饲料的犊牛断奶体重较高，断奶后生长速度也较快。因此，预断奶饲养对较高的断奶体重和断奶后较好的生长速度很重要。
