Ike Kelechi A, Casper David P, Hansen William P, Scott Mark, Anele Uchenna Y
College of Science and Technology, North Carolina Agricultural and Technical State University Greensboro NC 27401.
Casper's Calf Ranch, Freeport, IL 61032; Department of Animal Sciences, North Carolina Agricultural and Technical State University Greensboro NC 27401.
J Dairy Sci. 2024 Dec;107(12):10667-10679. doi: 10.3168/jds.2024-25262. Epub 2024 Aug 16.
Galacto-oligosaccharide (GOS) is a prebiotic isolated from whey. This study evaluated the optimal inclusion rate for improving the growth and health performance of neonatal calves. Eighty-eight 2 to 5-d old Holstein bull calves were blocked by initial BW and randomly allocated to 1 of 4 treatments using a randomized complete block design. Treatments comprised a 22:20 (CP:fat) AA-balanced milk replacer (MR) with GOS added at the rate of 0 g/d (control or GOS0), 2 g/d (GOS2), 4 g/d (GOS4), and 8 g/d (GOS8). Calves received 0.283 kg MR in 1.9 L fed 2×/day for the first 14 d, then increased to 0.42 kg in 2.84 L fed 2×/d through d 35, followed by 0.42 kg MR in 2.84 L fed 1×/d through d 42, followed by weaning. The GOS inclusion rate remained constant as the milk volume increased. Calves fed GOS at 2, 4, and 8 g/d demonstrated similar growth performance compared with calves fed GOS0. Calves fed GOS4 demonstrated a carryover effect into postweaning resulting in a tendency for increased BW (82.5, 83.0, 85.3, and 83.1 kg for GOS0, GOS2, GOS4, and GOS8, respectively), BW gains (37.8, 38.2, 41.3, and 38.6 kg), and ADG (687, 696, 751, and 701 g/d). The ADG was increased by 9.3% when feeding calves GOS4 compared with calves fed GOS0. Calf starter DMI was greater at 7 (1.73,1.86, 1.95, and 1.83 kg/d) and 8 (2.34, 2.50, 2.60, 2.49 kg/d) wk of age for calves fed GOS4 compared with calves fed GOS0, with the remaining treatments being intermediate and similar. Feed conversion (0.552, 0.529, 0.563, and 0.545 kg/kg) was greater for calves fed GOS0 and GOS4 g/d compared with calves fed GOS2, with calves fed GOS8 being intermediate and similar. Body frame gains were similar for calves fed all GOS inclusion rates. A treatment by week interaction at wk 2 indicated that calves fed GOS2 demonstrated a greater number of of days with a fecal score = 0 than calves fed the remaining treatments, indicating less scours. In conclusion, supplementing GOS to a MR at 4 g/d fed to neonatal calves improved growth performance without compromising health conditions.
低聚半乳糖（GOS）是一种从乳清中分离出来的益生元。本研究评估了提高新生犊牛生长性能和健康状况的最佳添加率。88头2至5日龄的荷斯坦公牛犊按初始体重进行分组，并采用随机完全区组设计随机分配到4种处理中的1种。处理包括一种22:20（粗蛋白：脂肪）氨基酸平衡的代乳粉（MR），添加GOS的量分别为0 g/天（对照组或GOS0）、2 g/天（GOS2）、4 g/天（GOS4）和8 g/天（GOS8）。犊牛在第1个14天每天分2次饲喂1.9升含0.283千克MR的代乳粉，然后在第35天前每天分2次饲喂2.84升含0.42千克MR的代乳粉，之后在第42天前每天分1次饲喂2.84升含0.42千克MR的代乳粉，随后断奶。随着乳量增加，GOS添加率保持不变。与饲喂GOS0的犊牛相比，饲喂2、4和8 g/天GOS的犊牛生长性能相似。饲喂GOS4的犊牛断奶后有持续效应，导致体重有增加趋势（GOS0、GOS2、GOS4和GOS8组的体重分别为82.5、83.0、85.3和83.1千克）、体重增加量（分别为37.8、38.2、41.3和38.6千克）和平均日增重（分别为687、696、751和701克/天）。与饲喂GOS0的犊牛相比，饲喂GOS4的犊牛平均日增重提高了9.3%。在7周龄（分别为1.73、1.86、1.95和1.83千克/天）和8周龄（分别为2.34、2.50、2.60和2.49千克/天）时，饲喂GOS4的犊牛犊牛开食料干物质采食量高于饲喂GOS0的犊牛，其余处理处于中间水平且相似。与饲喂GOS2的犊牛相比，饲喂GOS0和4 g/天GOS的犊牛饲料转化率（分别为0.552、0.529、0.563和0.545千克/千克）更高，饲喂GOS8的犊牛处于中间水平且相似。所有GOS添加率组的犊牛体躯生长量相似。第2周时处理与周龄的交互作用表明，与饲喂其他处理的犊牛相比，饲喂GOS2的犊牛粪便评分为0的天数更多，表明腹泻更少。总之，给新生犊牛饲喂的代乳粉中添加4 g/天的GOS可提高生长性能，且不影响健康状况。
