van Alst G, Robison O W
Department of Animal Science, North Carolina State University, Raleigh 27695-7621.
J Anim Sci. 1992 Jul;70(7):2078-85. doi: 10.2527/1992.7072078x.
Data were obtained from 1,954 Duroc and 2,252 Yorkshire purebred and crossbred progeny sired by 34 Duroc and 32 Yorkshire boars, respectively. Boars were purchased from the North Carolina Swine Evaluation Station during August 1983 to December 1988. Boars were selected to represent high and low indexes at the test station. Progeny were raised and tested under conditions similar to commercial pig production at the Tidewater Research Station. For each breed of boar (Duroc and Yorkshire), breed type (purebred and crossbred), and sex (castrates and gilts) of progeny, regression coefficients of progeny traits on each sire trait were computed. Progeny traits were ADG, days to 104.3 kg BW (DAYS), backfat thickness (BF), and feed conversion ratio (FC). Sire traits were ADG, DAYS, BF, FC, and INDEX. Effects of boar test group and progeny test group were included in the models. Averaged over breed type and sex, a 25-unit (1 SD) increase in sire INDEX resulted in 14.5 g more ADG, 3.2 fewer DAYS, .57 mm more BF, and .017 lower FC in Durocs and 5.6 g more ADG, .01 more DAYS, .81 mm less BF, and .083 lower FC in Yorkshires. The low magnitude and variable signs of some regression coefficients suggested that predictions of progeny performance from performance of individual sires at the North Carolina Swine Evaluation Station were not very reliable. Differences between regressions for purebreds and crossbreds implied small correlations between the two breed types. Differences between Durocs and Yorkshires indicated that genetic parameters might not be the same for the two breeds.
数据分别取自1954头杜洛克猪以及2252头约克夏纯种猪和杂交后代，这些后代分别由34头杜洛克公猪和32头约克夏公猪所生。公猪于1983年8月至1988年12月期间从北卡罗来纳州种猪评估站购入。公猪在测试站被挑选出来以代表高指数和低指数。后代在潮水研究站类似商业养猪生产的条件下饲养和测试。对于每种公猪品种（杜洛克和约克夏）、后代的品种类型（纯种和杂交）以及性别（去势公猪和后备母猪），计算了后代性状对每个父本性状的回归系数。后代性状包括平均日增重（ADG）、达到104.3千克体重的天数（DAYS）、背膘厚度（BF）和饲料转化率（FC）。父本性状包括ADG、DAYS、BF、FC和INDEX。模型中纳入了公猪测试组和后代测试组的影响。在品种类型和性别上进行平均，父本INDEX增加25个单位（1个标准差），杜洛克猪的ADG增加14.5克、DAYS减少3.2天、BF增加0.57毫米、FC降低0.017，约克夏猪的ADG增加5.6克、DAYS增加0.01天、BF减少0.81毫米、FC降低0.083。一些回归系数的低幅度和可变符号表明，根据北卡罗来纳州种猪评估站个体公猪的性能来预测后代性能并非非常可靠。纯种和杂交后代回归之间的差异意味着这两种品种类型之间的相关性较小。杜洛克猪和约克夏猪之间的差异表明这两个品种的遗传参数可能不同。
