Ockenden Emma M, Russo Victoria M, Leury Brian J, Giri Khageswor, Wales William J
Agriculture Victoria, Ellinbank, VIC 3821, Australia.
Faculty of Agriculture, Ecosystem, Food and Forest Sciences, The University of Melbourne, Parkville, VIC 3010, Australia.
Animals (Basel). 2023 Feb 24;13(5):829. doi: 10.3390/ani13050829.
Feeding increased volumes of milk in the preweaning phase has been shown to improve growth, morbidity and mortality rates in calves (). This experiment enlisted 20 Holstein-Friesian dairy replacement calves from birth until weaning (at 10 weeks of age) and assessed the effect of feeding either 4 L (Low) or 8 L (High) of milk per calf per day on their growth, immune competence and metabolic characteristics. The responsiveness of these systems was compared through a vaccination immune challenge. Calves in the High treatment group were significantly heavier from two weeks of age and were 19 kg heavier than calves in the Low treatment group at weaning. Calves in the High treatment group also exhibited greater immune responses, with significantly higher white cell counts and neutrophil counts than calves in the Low treatment group post-vaccination. Calves in the High treatment group also had lower beta-hydroxybutyrate both pre- and post-vaccination, and higher glucose and insulin levels post-vaccination, indicating superior metabolic characteristics. Calves had ad libitum access to lucerne hay () and a commercial concentrate. Solid feed intakes were mostly the same between treatments, with differences in hay intake only detected at 7 and 8 weeks of age. Results from this experiment are indicative of a positive influence of accelerated preweaning nutrition on growth, immune response and metabolic characteristics.
在断奶前阶段增加牛奶喂量已被证明可改善犊牛的生长、发病率和死亡率（）。本实验选取了20头荷斯坦-弗里生代乳用犊牛，从出生到断奶（10周龄），评估每天每头犊牛喂4升（低）或8升（高）牛奶对其生长、免疫能力和代谢特征的影响。通过疫苗免疫挑战比较这些系统的反应性。高处理组的犊牛从两周龄起体重显著更重，断奶时比低处理组的犊牛重19千克。高处理组的犊牛也表现出更强的免疫反应，接种疫苗后白细胞计数和中性粒细胞计数显著高于低处理组的犊牛。高处理组的犊牛在接种疫苗前后β-羟基丁酸水平也较低，接种疫苗后葡萄糖和胰岛素水平较高，表明其代谢特征更优。犊牛可自由采食苜蓿干草（）和一种商业浓缩饲料。各处理间固体饲料摄入量大多相同，仅在7周龄和8周龄时检测到干草摄入量存在差异。本实验结果表明断奶前加速营养对生长、免疫反应和代谢特征有积极影响。
