Jenkins T G, Ferrell C L
ARS, USDA, US Meat Animal Research Center, Clay Center, NE 68933-0166, USA.
J Anim Sci. 2004 Jun;82(6):1876-81. doi: 10.2527/2004.8261876x.
Production data were collected on mature cows produced by mating Angus and Hereford (pooled AH), Brahman (Bh) and Boran (Br), and Tuli, a tropically adapted Bos taurus, sires by AI or natural service to Angus and Hereford cows. These cows were mated to Charolais bulls for the purpose of this study. Within each sire breed of cow, cows were assigned randomly to one of three feeding rates, 49 or 76 g of DMI/ BW0.75 or ad libitum (10 to 12 cows/feeding rate group), with weekly individual animal feed consumption recorded. Lactation yields were recorded via the weigh-suckle-weigh protocol at approximately 14, 28, 56, 84, 112, 140, 168, and 196 d postpartum for each cow/calf pair. Means for milk yield at peak lactation, total milk yields, calf birth weight, age-adjusted weaning weights, preweaning daily gain, and feed efficiency were estimated. Peak yield (kg/d) for Bh (10.3 +/- 0.36) was greater (P < 0.05) than for Tuli (9.0 +/- 0.31). Total yield (kg, 212 d) for Bh (1802 +/- 68) was greater (P < 0.05) than for Tuli (1532 +/- 59). Birth weight of AH (44 +/- 0.9) was heavier than for Bh and Br (P < 0.05). Preweaning daily calf gain (g/d) and adjusted weaning weight (kg) of Bh (813 +/- 28, 212 +/- 6.1) and Br (766 +/- 24, 202 +/- 5.1) differed (P < 0.05) from AH (589 +/- 24, 169 +/- 5.2) and Tuli (634 +/- 24, 176 +/- 5.3). Efficiency estimates (grams of adjusted weaning weight/kilograms DMI of the cow) for Bh (88 +/- 2.5) and Br (85 +/- 2.1) exceeded (P < 0.05) those for Tuli (74 +/- 2.1) and AH (73 +/- 2.1). Bos indicus breed crosses exhibited greater peak and total yield, lower birth weight, greater daily gain and adjusted weaning weight, and higher feed efficiency than did Bos taurus breed crosses (P < 0.05). Total yield, daily gain, adjusted weaning weight, and feed efficiency were higher (P < 0.05) for cows sired by bulls from tropically adapted breeds, and the peak yield was less (P < 0.10). Tuli exhibited lower total yield and birth weight than did Angus/Hereford (P < 0.05). The efficiency of crossbred Tuli cows did not differ from Angus/Hereford F1 females, but neither equaled the efficiency of crossbred cows produced using Bos indicus breeds.
收集了通过人工授精或自然交配，用安格斯牛和赫里福德牛（合并为AH）、婆罗门牛（Bh）、博拉牛（Br）以及热带适应性瘤牛图利牛的公牛与安格斯牛和赫里福德牛母牛交配所产成熟母牛的生产数据。为了本研究，这些母牛与夏洛莱公牛进行交配。在每个母牛的父本品种内，母牛被随机分配到三种采食量之一，即49克或76克干物质采食量/体重0.75次方，或自由采食（每组10至12头母牛），并记录每周每头动物的采食量。通过称重-哺乳-称重方案，在产后约14、28、56、84、112、140、168和196天记录每对母牛/犊牛的泌乳量。估算了泌乳高峰期的产奶量、总产奶量、犊牛出生体重、年龄校正断奶体重、断奶前日增重和饲料效率。婆罗门牛的泌乳高峰期产量（千克/天）（10.3±0.36）高于图利牛（9.0±0.31）（P<0.05）。婆罗门牛的总产奶量（千克，212天）（1802±68）高于图利牛（1532±59）（P<0.05）。AH的犊牛出生体重（44±0.9）高于婆罗门牛和博拉牛（P<0.05）。婆罗门牛（813±28，212±6.1）和博拉牛（766±24，202±5.1）的断奶前犊牛日增重（克/天）和校正断奶体重（千克）与AH（589±24，169±5.2）和图利牛（634±24，176±5.3）不同（P<0.05）。婆罗门牛（88±2.5）和博拉牛（85±2.1）的效率估算值（校正断奶体重克数/母牛干物质采食量千克数）高于图利牛（74±2.1）和AH（73±2.1）（P<0.05）。印度瘤牛品种杂交后代比欧洲牛品种杂交后代表现出更高的泌乳高峰期和总产奶量、更低的出生体重、更高的日增重和校正断奶体重以及更高的饲料效率（P<0.05）。由热带适应性品种公牛所产母牛的总产奶量、日增重、校正断奶体重和饲料效率更高（P<0.05），而泌乳高峰期产量更低（P<0.10）。图利牛的总产奶量和出生体重低于安格斯/赫里福德牛（P<0.05）。图利牛杂交母牛的效率与安格斯/赫里福德F1代母牛无差异，但均不及使用印度瘤牛品种所产杂交母牛的效率。
