Autonomous Agrarian University Antonio Narro, Department of Animal Nutrition, Saltillo, Mexico.
Autonomous Agrarian University Antonio Narro, Department of Veterinary Science, Torreon, Mexico.
Trop Anim Health Prod. 2021 Sep 21;53(5):467. doi: 10.1007/s11250-021-02903-z.
The objective of this study was to evaluate growth performance, and mammary gland parenchyma (PAR) development in Holstein female calves fed whole milk combined with milk replacer for 15% total solids (15TS) or only milk (11% TS; 11TS). The effects of zilpaterol hydrochloride (ZH) and an estrogenic implant (EI) on growth performance, serum metabolites, and PAR development in post-weaning calves (63-90 days of age) fed 15TS or 11TS were also investigated. In the first phase, 78 calves were randomly divided into two groups (n = 39/group), 15TS, or 11TS (5 to 8 L/day; starter ad libitum). After weaning, calves were randomly assigned to four treatments, no EI, EI, ZH, and ZH-EI. In phase 1, 15TS calves had greater (P < 0.01) average body weight at weaning than 11TS calves (82.0 ± 5.8 vs. 74.1 ± 5.7 kg). Pre-weaning average daily gain (718 ± 67 vs. 576 ± 64 g/day) was higher (P < 0.01) for 15TS calves than 11TS calves. Feed/gain (1.5 ± 0.3 vs. 1.8 ± 0.3 kg of DMI/kg of gain) was lower (P < 0.01) for 15TS calves than 11TS calves. PAR area (8.8 ± 3.3 vs. 5.0 ± 1.6 cm) was greater (P < 0.01) for 15TS calves than 11TS calves. No differences (P > 0.10) in average daily gain (986 ± 79 g/day across treatments) were observed in calves receiving ZH, EI, or ZH-EI fed 15TS or 11TS diets previously. However, the PAR area of 15TS calves administered ZH-EI was 2.2 times greater (P < 0.01) than 11TS calves with no ZH and CI. This study demonstrated the benefits of supplying milk with 15% TS for enhancing overall animal growth and PAR development. Further use of ZH and EI during the post-weaning period did improve mammary PAR growth.
本研究旨在评估 15%总固体（15TS）全奶与代乳料组合或仅 11%总固体（11TS）奶喂养的荷斯坦雌性犊牛的生长性能和乳腺实质（PAR）发育。还研究了齐帕特罗盐酸（ZH）和雌激素埋植剂（EI）对接受 15TS 或 11TS 喂养的断奶后（63-90 日龄）犊牛生长性能、血清代谢物和 PAR 发育的影响。在第一阶段，78 头犊牛随机分为两组（每组 39 头），15TS 或 11TS（5-8 L/天；自由采食开食料）。断奶后，犊牛随机分为 4 种处理组：无 EI、EI、ZH 和 ZH-EI。在第 1 阶段，15TS 犊牛的断奶平均体重（82.0±5.8 kg）高于 11TS 犊牛（74.1±5.7 kg）（P<0.01）。15TS 犊牛的预饲平均日增重（718±67 g/天）高于 11TS 犊牛（576±64 g/天）（P<0.01）。15TS 犊牛的饲料/增重（1.5±0.3 kg 的 DMI/kg 增重）低于 11TS 犊牛（1.8±0.3 kg 的 DMI/kg 增重）（P<0.01）。15TS 犊牛的 PAR 面积（8.8±3.3 cm）大于 11TS 犊牛（5.0±1.6 cm）（P<0.01）。在接受 ZH、EI 或 ZH-EI 喂养的 15TS 或 11TS 日粮的犊牛中，未观察到平均日增重（15TS 犊牛为 986±79 g/天，11TS 犊牛为 986±79 g/天）的差异（P>0.10）。然而，接受 ZH-EI 处理的 15TS 犊牛的 PAR 面积比未接受 ZH 和 CI 的 11TS 犊牛大 2.2 倍（P<0.01）。本研究表明，用 15% TS 的牛奶喂养可提高动物整体生长和 PAR 发育。在断奶后期间进一步使用 ZH 和 EI 可改善乳腺 PAR 生长。
