Dairy and Food Science Department, South Dakota State University, Brookings 57007.
Dairy and Food Science Department, South Dakota State University, Brookings 57007.
J Dairy Sci. 2019 Sep;102(9):8108-8119. doi: 10.3168/jds.2019-16314. Epub 2019 Jul 10.
Our objective was to evaluate growth performance, nutrient utilization, and health of calves supplemented with condensed whey solubles (CWS). Twenty-four Holstein calves (2 d old) in hutches were used in a 12-wk randomized complete block design study. Calves were blocked by birth date and sex. Treatments were (1) control (CON) with no supplement and (2) 50 g/d of CWS. Preweaning CWS was fed with milk and postweaning CWS was top-dressed on starter pellets. Calves were fed 2.83 L of pasteurized milk 2×/d during wk 1 to 5, 1×/d in wk 6, and weaned at d 42. Calves had ad libitum access to starter pellets and water. Individual intakes of milk and starter pellets were measured daily. Fecal scores (0 = firm, 3 = watery) and respiratory scores (healthy ≤3, sick ≥5), calculated from the sum of scores for rectal temperature, cough, ocular, and nasal discharge, were recorded daily. Body weights (BW), frame growth, and jugular blood samples were taken once every week at 3 h after the morning feeding. Fecal grab samples were collected in wk 12 for analysis of apparent total-tract digestibility. Data were analyzed using MIXED procedures of SAS 9.4 (SAS Institute Inc., Cary, NC) with repeated measures. Total dry matter intake was greater in calves fed CWS compared with CON. Calves fed CWS tended to have greater BW during the postweaning period. Gain:feed, average daily gains, withers heights, and concentrations of plasma urea nitrogen were not different. Concentrations of plasma β-hydroxybutyrate were greater in calves fed CWS compared with CON. Serum glucose concentrations were greater in calves fed CON during the preweaning stage, but similar concentrations were found between treatments during the postweaning stage. Rumen pH, ammonia-N, and total volatile fatty acids were similar between treatments. The acetate:propionate ratio was greater in calves fed CWS. The apparent total-tract digestion of nutrients was similar; however, CON tended to have greater digestion of neutral detergent fiber. Fecal scores were not different, but a treatment by week interaction was observed. Supplementing CWS improved starter intake, postweaning BW, β-hydroxybutyrate, fecal scores, and maintained frame growth.
我们的目的是评估补充浓缩乳清可溶性物（CWS）对犊牛生长性能、养分利用和健康的影响。24 头荷斯坦犊牛（2 日龄）在畜栏中进行了为期 12 周的随机完全区组设计研究。犊牛按出生日期和性别分组。处理措施为（1）对照组（CON）不添加任何补充剂，（2）每天补充 50g 的 CWS。CWS 在哺乳期与牛奶一起饲喂，断奶后作为犊牛颗粒料的顶部添加物。犊牛在第 1 周到第 5 天每天接受 2.83 升巴氏消毒牛奶 2 次，第 6 天每天 1 次，在第 42 天断奶。犊牛自由采食犊牛颗粒料和水。每天记录牛奶和犊牛颗粒料的个体摄入量。粪便评分（0 = 坚硬，3 = 水样）和呼吸评分（健康评分≤3，患病评分≥5），由直肠温度、咳嗽、眼部和鼻腔分泌物评分总和计算得出，每天记录。每周在上午喂养后 3 小时进行一次体重（BW）、框架生长和颈静脉血液采样。在第 12 周采集粪便混合样本，用于分析表观全肠道消化率。使用 SAS 9.4（SAS Institute Inc.，Cary，NC）的 MIXED 程序对数据进行分析，采用重复测量。与 CON 组相比，饲喂 CWS 的犊牛总干物质采食量更高。饲喂 CWS 的犊牛在断奶后阶段 BW 增加更多。增重：采食量、平均日增重、肩高和血浆尿素氮浓度没有差异。饲喂 CWS 的犊牛血浆 β-羟丁酸浓度高于 CON 组。CON 组犊牛在哺乳期阶段的血清葡萄糖浓度更高，但在断奶后阶段，两种处理方式的血清葡萄糖浓度相似。瘤胃 pH、氨氮和总挥发性脂肪酸在两种处理方式之间没有差异。饲喂 CWS 的犊牛乙酸：丙酸比值更高。两种处理方式的养分表观全肠道消化率相似；但 CON 组的中性洗涤纤维消化率更高。粪便评分没有差异，但处理方式与周次之间存在交互作用。补充 CWS 可提高犊牛的开食料采食量、断奶后 BW、β-羟丁酸、粪便评分并维持框架生长。
