Byrne C J, Fair S, English A M, Johnston D, Lonergan P, Kenny D A
1Animal & Grassland Research and Innovation Centre,Teagasc,Dunsany,C15 PW93 Co. Meath,Ireland.
3Department of Biological Sciences,University of Limerick,V94 T9PX Limerick,Ireland.
Animal. 2017 Sep;11(9):1531-1538. doi: 10.1017/S1751731117000350. Epub 2017 Feb 20.
Early-life nutrition affects calf development and thus subsequent performance. The aim of this study was to examine the effect plane of nutrition on growth, feeding behaviour and systemic metabolite concentrations of artificially reared dairy bull calves. Holstein-Friesian (F; n=42) and Jersey (J; n=25) bull calves with a mean±SD age (14±4.7 v. 27±7.2 days) and BW (47±5.5 v. 33±4.7 kg) were offered a high, medium or low plane of nutrition for 8 weeks using an electronic feeding system which recorded a range of feed-related events. Calves were weighed weekly and plasma samples were collected via jugular venipuncture on weeks 1, 4 and 7 relative to the start of the trial period. The calves offered a high plane of nutrition had the greatest growth rate. However, the increased consumption of milk replacer led to a reduction in feed efficiency. Holstein-Friesian calves offered a low plane of nutrition had the greatest number of daily unrewarded visits to the feeder (P<0.001). β-hydroxybutyrate (BHB) concentrations were greater in F calves on a low plane of nutrition (P<0.001). Although there was no effect of plane of nutrition, BHB concentrations in F calves increased before weaning, concomitant with an increase in concentrate consumption. Urea concentrations were unaffected by plane of nutrition within either breed. Jersey calves on a low plane of nutrition tended to have lower triglycerides than those on a high plane (P=0.08), but greater than those on a medium plane (P=0.08). Holstein-Friesian calves offered a high plane of nutrition tended to have greater triglyceride concentrations than those on a medium plane (P=0.08). Triglycerides increased from the start to the end of the feeding period (P<0.05), across both breeds. A medium plane of nutrition resulted in a growth, feeding behaviour and metabolic response comparable with a high plane of nutrition in pre-weaned bull calves of both F and J breeds.
早期营养会影响犊牛发育，进而影响其后续生产性能。本研究旨在探究营养水平对人工饲养的奶牛公犊牛生长、采食行为和全身代谢物浓度的影响。采用电子饲喂系统，为平均年龄±标准差分别为（14±4.7对27±7.2天）、体重分别为（47±5.5对33±4.7千克）的荷斯坦 - 弗里生（F；n = 42）和泽西（J；n = 25）公犊牛提供高、中、低三种营养水平的饲料，为期8周，该系统记录了一系列与饲料相关的事件。每周对犊牛进行称重，并在试验期开始后的第1、4和7周通过颈静脉穿刺采集血浆样本。提供高营养水平的犊牛生长速率最快。然而，代乳粉消耗量的增加导致饲料效率降低。提供低营养水平的荷斯坦 - 弗里生犊牛每天对饲喂器无奖励访问的次数最多（P<0.001）。低营养水平的F犊牛中β - 羟基丁酸（BHB）浓度更高（P<0.001）。尽管营养水平没有影响，但F犊牛在断奶前BHB浓度升高，同时精饲料消耗量增加。两个品种内，尿素浓度均不受营养水平的影响。低营养水平的泽西犊牛甘油三酯含量往往低于高营养水平的犊牛（P = 0.08），但高于中营养水平的犊牛（P = 0.08）。提供高营养水平的荷斯坦 - 弗里生犊牛甘油三酯浓度往往高于中营养水平的犊牛（P = 0.08）。两个品种的犊牛在饲喂期内甘油三酯均从开始到结束有所增加（P<0.05）。对于F和J两个品种的断奶前犊牛，中等营养水平所带来的生长、采食行为和代谢反应与高营养水平相当。
