Virgínio Júnior Gercino Ferreira, Duranton Cécile Anna Jeanne, de Paula Marilia Ribeiro, Bittar Carla Maris Machado
Minas Gerais Agricultural Research Agency, Experimental Field of Montes Claros, Montes Claros, Minas Gerais, 39404-128, Brazil.
Department of Animal Science, Luiz de Queiroz College of Agriculture, University of São Paulo, Piracicaba, 13418-260, Brazil.
Anim Biosci. 2024 Jun;37(6):1031-1040. doi: 10.5713/ab.23.0225. Epub 2024 Jan 20.
This study aimed to evaluate the effect of feeding milk replacer (MR) with varying levels of lactose and the increased supply of total solids (from 750 to 960 g/d) on performance, blood metabolites, and health of Holstein male calves during the preweaning period.
Forty newborn Holstein calves (10 per treatment) were blocked according to birth weight and date of birth and distributed in a randomized block design to different liquid diets: Whole milk powder (WMP) diluted to 125 g/L solids; MR with 48% lactose (48L), diluted to 125 g/L solids; MR with 53% lactose (53L), diluted to 125 g/L solids; 53L MR corrected to 160 g/L solids (16TS) by the inclusion of a solid corrector. Calves were individually housed in wood hutches, fed 6 L/d of the liquid diet, and had free water and starter concentrate access. The study lasted 56 days.
Liquid diet intake was higher for calves fed 16TS than for other treatments. Calves fed 16TS presented higher protein and fat intake, followed by those fed WMP and the 48L or 53L MRs. Lactose intake was higher for 16TS-fed calves, followed by 53L, 48L, and WMP-fed calves. Starter and total dry matter intake did not differ among liquid diets. The average daily gain was higher for 16TS than 48L-fed calves, with the other treatments being intermediary. The lowest feed efficiency was observed for calves fed 48L. No effects on health were observed, as well as on selected blood metabolites, except for albumin concentration, which was higher for calves fed 16TS and WMP.
Higher total solids content (160 g/L) in MR increases nutrient intake and consequently improves the performance of dairy calves. Feeding MRs with levels of lactose up to 53% of the DM had no deleterious effect on the performance or health of the calves.
本研究旨在评估不同乳糖水平的代乳粉（MR）以及总固体供应量增加（从750克/天增加到960克/天）对荷斯坦公犊牛断奶前期生长性能、血液代谢物和健康状况的影响。
40头新生荷斯坦犊牛（每组10头）按出生体重和出生日期进行分组，并采用随机区组设计分配到不同的液体日粮中：全脂奶粉（WMP）稀释至125克/升固体；乳糖含量为48%的MR（48L），稀释至125克/升固体；乳糖含量为53%的MR（53L），稀释至125克/升固体；通过添加固体校正剂将53L MR校正至160克/升固体（16TS）。犊牛单独饲养在木制犊牛栏中，每天饲喂6升液体日粮，并可自由饮水和采食开食料。研究持续56天。
饲喂16TS的犊牛液体日粮摄入量高于其他处理组。饲喂16TS的犊牛蛋白质和脂肪摄入量较高，其次是饲喂WMP以及48L或53L MR的犊牛。饲喂16TS的犊牛乳糖摄入量较高，其次是53L、48L和饲喂WMP的犊牛。不同液体日粮间开食料和总干物质摄入量无差异。16TS组犊牛的平均日增重高于48L组，其他处理组居中。饲喂48L的犊牛饲料效率最低。除白蛋白浓度外，未观察到对健康和选定血液代谢物的影响，饲喂16TS和WMP的犊牛白蛋白浓度较高。
MR中较高的总固体含量（160克/升）可增加营养物质摄入量，从而提高犊牛的生长性能。饲喂乳糖含量高达干物质53%的MR对犊牛的生长性能或健康无有害影响。
