Schubert Dana Carina, Chuppava Bussarakam, Hoffmans Sandra, Pries Martin, Visscher Christian, Kamphues Josef, Abd El-Wahab Amr
Institute for Animal Nutrition, University of Veterinary Medicine Hannover, Foundation, Bischofsholer Damm 15, D-30173 Hannover, Germany.
Landwirtschaftskammer Nordrhein-Westfalen, Versuchs- und Bildungszentrum Landwirtschaft, Haus Riswick, D-47533 Kleve, Germany.
Animals (Basel). 2022 Jul 8;12(14):1756. doi: 10.3390/ani12141756.
In the present study, a drinking amount of 10 L of milk replacer (MR) was allowed to dairy calves in order to approach the natural drinking behavior. The question is: how much protein is required by calves in order to achieve an intended growth rate? For this reason, sixty-eight pre-weaned Holstein calves were divided into two groups and fed with 10 L/d of MR containing either 22% protein (MR22) or 19% protein (MR19) at an almost comparable energy intake. Effects on performance, metabolic status, and health were compared. Feed intake, growth performance, and health status were monitored during the pre-transition, transition, and postweaning phase (until 157 d of age). Total feed intake, and intake of MR, body weight (BW), and average daily gain (ADG) were not significantly different between MR22 and MR19 during the entire experimental period (p > 0.05). At d 42, calves in MR19 group showed greater serum levels of growth hormone (16.2 vs. 22.2 ng/mL; p = 0.02), insulin-like growth factor 1 (262 vs. 291 ng/mL; p = 0.03), and urea (2.86 vs. 3.04 mmol/L; p < 0.01). The results of the present study suggested that when high amounts of MR are provided, the protein content in MR can be reduced to 19% without any adverse effects on growth performance as well as on health status of dairy calves.
在本研究中，为了接近自然饮水行为，给犊牛提供了10升代乳粉（MR）的饮水量。问题是：犊牛为了达到预期的生长速度需要多少蛋白质？因此，将68头断奶前的荷斯坦犊牛分为两组，在能量摄入量几乎相当的情况下，分别饲喂每天10升含22%蛋白质的代乳粉（MR22）或含19%蛋白质的代乳粉（MR19）。比较了对生产性能、代谢状态和健康的影响。在过渡前、过渡和断奶后阶段（直至157日龄）监测采食量、生长性能和健康状况。在整个实验期间，MR22组和MR19组之间的总采食量、代乳粉采食量、体重（BW）和平均日增重（ADG）没有显著差异（p>0.05）。在第42天，MR19组犊牛的生长激素血清水平更高（16.2对22.2 ng/mL；p = 0.02），胰岛素样生长因子1（262对291 ng/mL；p = 0.03），以及尿素（2.86对3.04 mmol/L；p<0.01）。本研究结果表明，当提供大量代乳粉时，代乳粉中的蛋白质含量可降至19%，而对犊牛的生长性能和健康状况没有任何不利影响。
