Brost K N, Pister M L, Paulus Compart D M, Drackley J K
Department of Animal Sciences, University of Illinois, Urbana, IL 61801.
Land O'Lakes, Inc., 4001 Lexington Ave N, Arden Hills, MN, 55126.
J Dairy Sci. 2025 Jul 31. doi: 10.3168/jds.2025-26672.
The use of yeast products, phytogenics, and direct-fed microbials (DFM) have been shown to improve health and growth performance of dairy calves. More recently, combining nutrients and additives to optimize calf performance has become a growing interest area. The purpose of this study was to determine if feed additives in milk replacer (MR) and starter could improve health and growth of Holstein calves through 13 wk of age. Ninety male Holstein calves <4 d of age were assigned to 1 of 3 treatments. Calves were individually housed in outdoor hutches through d 56, then moved to group pens through d 92. Treatments were a control MR and pelleted starters with no additives (CON); a MR with phytogenics and yeast extract plus a starter with a blend of phytogenics and yeast products (CTP); and the same CTP MR with a starter containing an experimental blend of phytogenics, yeast products, and DFM (CEP). Diets were formulated as follows: MR contained 22% CP and 20% fat and starters contained at least 16% CP and 4% fat (as-fed basis). Average initial BW were 42.1 (±5.9) kg for CON, 42.9 (±4.9) kg for CTP, and 43.3 (±5.5) kg for CEP. Calves were fed MR at a rate of 600 g/d (as fed), reconstituted to 13% solids. This amount was fed from d 0 to 42 when the single step-down weaning process started by discontinuing the evening MR feeding. After d 49, MR was completely discontinued but calves stayed in individual hutches through d 56 and then were moved to group housing. During the group-housed portion of the experiment, calves were provided with ad libitum pelleted starters and water. Health scores were collected twice daily from d 1 to 56, and once daily from d 57 to 70. Body weight and frame measurements were collected weekly. Average ME intake was consistently greater for CTP throughout the trial, and starter ME intake was greater compared with CON for wk 4 to 13. Final BW was greater for CTP and CEP for wk 1 to 13 relative to CON. Frame growth was improved for CTP and CEP during wk 1 to 8 in comparison to CON. Feed efficiency tended to be greater for CTP and CEP compared with CON during wk 9 to 13. There was a tendency for lower incidence of scours for calves fed CTP, and overall health and need for medication were improved for calves fed both CTP and CEP compared with CON. Results of this study indicate improvements in pre- and postweaning health and growth of calves fed blends of yeast products, phytogenics, and DFM in MR and pelleted starters.
已证明使用酵母产品、植物源添加剂和直接投喂微生物（DFM）可改善犊牛的健康状况和生长性能。最近，将营养物质和添加剂结合起来以优化犊牛性能已成为一个日益受关注的领域。本研究的目的是确定代乳粉（MR）和开食料中的饲料添加剂是否能在13周龄前改善荷斯坦犊牛的健康状况和生长情况。将90头4日龄以下的雄性荷斯坦犊牛分配到3种处理中的1种。犊牛在56日龄前单独饲养在室外犊牛栏中，然后在92日龄前转移到群养栏中。处理方式为：对照代乳粉和无添加剂的颗粒开食料（CON）；含植物源添加剂和酵母提取物的代乳粉以及含植物源添加剂和酵母产品混合物的开食料（CTP）；与CTP相同的代乳粉以及含植物源添加剂、酵母产品和DFM实验混合物的开食料（CEP）。日粮配方如下：代乳粉含22%粗蛋白和20%脂肪，开食料含至少16%粗蛋白和4%脂肪（以风干基础计）。CON组犊牛的平均初始体重为42.1（±5.9）千克，CTP组为42.9（±4.9）千克，CEP组为43.3（±5.5）千克。犊牛以600克/天（以风干计）的速度饲喂代乳粉，调制成13%的固体含量。该量从第0天喂至第42天，此时通过停止夜间代乳粉饲喂开始单步递减断奶过程。49日龄后，完全停止饲喂代乳粉，但犊牛在56日龄前一直留在单独的犊牛栏中，然后转移到群养舍。在实验的群养阶段，为犊牛提供自由采食的颗粒开食料和水。从第1天至56天每天收集两次健康评分，从第57天至70天每天收集一次。每周收集体重和体尺测量数据。在整个试验期间，CTP组的平均代谢能摄入量始终较高，在第4至13周，开食料的代谢能摄入量相对于CON组更高。在第1至13周，CTP组和CEP组的最终体重相对于CON组更大。与CON组相比，CTP组和CEP组在第1至8周的体尺生长有所改善。在第9至13周，CTP组和CEP组与CON组相比，饲料效率往往更高。饲喂CTP组的犊牛腹泻发病率有降低的趋势，与CON组相比，饲喂CTP组和CEP组的犊牛总体健康状况和用药需求均有所改善。本研究结果表明，在代乳粉和颗粒开食料中添加酵母产品、植物源添加剂和DFM的混合物可改善犊牛断奶前后的健康状况和生长情况。
