Harvey R W, Burns J C
Dept. of Anim. Sci., North Carolina State University, Raleigh 27695-7621.
J Anim Sci. 1988 May;66(5):1109-14. doi: 10.2527/jas1988.6651109x.
One hundred fifty Simmental-Hereford cows and calves were used in a 3-yr study to evaluate three creep grazing treatments and an early weaning treatment on cow and calf performance during midsummer (July to September). Calves were approximately 150 d of age and averaged 178.6 kg when treatments were initiated. Tifleaf pearl millet (Pennisetum Americanum L. Leeke) was used as the forage for two of the creep treatments, representing two cow stocking intensities of .466 (TLM1) and .239 (TLM2) ha of base hill land pasture/cow, and as pasture for early weaned calves. A red clover (Trifolium pratense L.)-Kentucky bluegrass (Poa pratensis L.) mixture was used as the other creep forage. Hill land pastures were similar for the mature cow units in all creep treatments. Calf average daily gains ranged from .93 to 1.10 kg and were not influenced (P greater than .05) by treatment. Calf gains per hectare were similar for the control, red clover and TLM1 treatments. The TLM2 and early weaning treatments resulted in increases of 105.4 and 39.1 kg of calf gain/ha (P less than .05) compared with the control. When calves were allowed to creep graze millet, decreasing the forage area from .466 to .239 ha per cow-calf unit resulted in an increase of 97.7 kg of calf gain/ha with no reduction in calf gain. Cows on the more intensively grazed millet creep treatment (TLM2) lost more weight (P less than .05) during midsummer than those on the TLM1 treatment, but they gained 18.5 kg more (P less than .10) weight than TLM1 cows between weaning and the start of winter feeding.
在一项为期3年的研究中,选用了150头西门塔尔-赫里福德母牛及其犊牛,以评估三种补饲放牧处理方式和一种早期断奶处理方式对盛夏(7月至9月)母牛和犊牛性能的影响。开始处理时,犊牛约150日龄,平均体重178.6千克。两种补饲处理方式使用了梯牧草珍珠粟(狼尾草属美洲狼尾草利克)作为牧草,分别代表两种母牛饲养密度,即每公顷基础山地牧场/母牛为0.466公顷(TLM1)和0.239公顷(TLM2),并作为早期断奶犊牛的牧场。另一种补饲牧草采用红三叶(三叶草属草原三叶草)-草地早熟禾(早熟禾属草地早熟禾)混合物。所有补饲处理方式中,成年母牛单位的山地牧场情况相似。犊牛平均日增重范围为0.93至1.10千克,不受处理方式影响(P大于0.05)。对照、红三叶和TLM1处理方式下,每公顷犊牛增重相似。与对照相比,TLM2和早期断奶处理方式每公顷犊牛增重分别增加了105.4千克和39.1千克(P小于0.05)。当犊牛可以补饲放牧珍珠粟时,将每头母牛-犊牛单位的牧草面积从0.466公顷减少到0.239公顷,每公顷犊牛增重增加了97.7千克,且犊牛增重没有减少。在更密集放牧珍珠粟的补饲处理方式(TLM2)下的母牛,在盛夏期间比TLM1处理方式下的母牛体重损失更多(P小于0.05),但在断奶至冬季开始喂食期间,它们比TLM1母牛多增重18.5千克(P小于0.10)。