Brown A H, Johnson Z B, Chewning J J, Brown C J
Dept. of Anim. Sci., University of Arkansas, Fayetteville 72701.
J Anim Sci. 1988 Oct;66(10):2524-9. doi: 10.2527/jas1988.66102524x.
Knowledge of the relationships between absolute growth rate (AGR), relative growth rate (RGR) and feed conversion (FCONV) of bulls in postweaning feedlot performance tests can give cattle producers important information for selecting superior sires. Weight gain and FCONV data that were collected during 16 yr were analyzed from 393 Angus and 340 Hereford bulls by 26 and 27 sires, respectively, that were individually fed in 140-d tests. Sire variance and covariance components were used to obtain heritability (h2) estimates for AGR, RGR and FCONV and the genetic correlations (rg) and phenotypic correlations (rp) among these traits. Respective mean AGR, RGR and FCONV were 1.27 +/- .14 kg/d, .4378 +/- .0395%/d and 7.32 +/- .58 kg/kg for the Angus and 1.28 +/- .12 kg/d, .4552 +/- .0388%/d and 6.56 +/- .46 kg/kg for the Hereford bulls. Estimates of h2 were similar for AGR and RGR in both Angus (.36 +/- .11 and .22 +/- .09) and Hereford (.33 +/- .11 and .20 +/- .09) bulls. The h2 estimates for FCONV were .14 +/- .07 for Angus and .13 +/- .08 for Herefords. For the Angus and Hereford bulls, respectively, rg were .86 +/- .09 and .86 +/- .13 between AGR and RGR, -.84 +/- .38 and -.74 +/- .49 between AGR and FCONV and -.84 +/- .49 and -.61 +/- .64 between RGR and FCONV. The rp were .80 +/- .03 and .68 +/- .04 between AGR and RGR, -.58 +/- .05 and -.51 +/- .05 between AGR and FCONV and -.71 +/- .04 and -.73 +/- .04 between RGR and FCONV for the Angus and Hereford bulls, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
了解断奶后育肥性能测试中公牛的绝对生长率（AGR）、相对生长率（RGR）和饲料转化率（FCONV）之间的关系，可为养牛生产者选择优质种公牛提供重要信息。对16年间收集的体重增加和FCONV数据进行了分析，分别来自393头安格斯公牛和340头赫里福德公牛，由26头和27头种公牛个体饲养140天进行测试。利用种公牛的方差和协方差成分来获得AGR、RGR和FCONV的遗传力（h2）估计值，以及这些性状之间的遗传相关性（rg）和表型相关性（rp）。安格斯公牛的平均AGR、RGR和FCONV分别为1.27±0.14千克/天、0.4378±0.0395%/天和7.32±0.58千克/千克，赫里福德公牛分别为1.28±0.12千克/天、0.4552±0.0388%/天和6.56±0.46千克/千克。安格斯和赫里福德公牛的AGR和RGR的h2估计值相似（分别为0.36±0.11和0.22±0.09，0.33±0.11和0.20±0.09）。安格斯和赫里福德公牛的FCONV的h2估计值分别为0.14±0.07和0.13±0.08。对于安格斯和赫里福德公牛，AGR和RGR之间的rg分别为0.86±0.09和0.86±0.13，AGR和FCONV之间分别为-0.84±0.38和-0.74±0.49，RGR和FCONV之间分别为-0.84±0.49和-0.61±0.64。安格斯和赫里福德公牛的AGR和RGR之间的rp分别为0.80±0.03和0.68±0.04，AGR和FCONV之间分别为-0.58±0.05和-0.51±0.05，RGR和FCONV之间分别为-0.71±0.04和-0.73±0.04。（摘要截于250字）
