Suzuki K, Nakagawa M, Katoh K, Kadowaki H, Shibata T, Uchida H, Obara Y, Nishida A
Graduate School of Agricultural Science, Tohoku University, Aoba-ku, Sendai, Miyagi Prefecture 981-8555, Japan.
J Anim Sci. 2004 Apr;82(4):994-9. doi: 10.2527/2004.824994x.
This study was intended to examine whether serum IGF-I concentration is appropriate for use as a physiological predictor for genetic improvement of meat production and meat quality traits in pigs. Heritabilities and genetic correlations were estimated for these traits. The Duroc breed used in this study was selected for seven generations for average daily BW gain (DG) from 30 to 105 kg of BW, loin-eye muscle area (EM), backfat thickness (BF), and intramuscular fat (IMF) content. Serum IGF-I concentration of boars and gilts at the fourth generation of selection and that of boars, gilts, and barrows from the fifth to seventh generations of selection were measured at 8 wk (IGFI-8W) for 832 animals and again at the time they reached 105 kg of BW (IGFI-105KG) for 834 animals. A multivariate REML procedure was used to estimate genetic parameters with a model incorporating generation of selection, sex, common environmental effect of litter, and individual additive genetic effects. Heritability estimates for IGFI-8W and IGFI-105KG were 0.23 +/- 0.02 and 0.26 +/- 0.03, respectively. The estimates of common environmental effect for IGFI-8W and IGFI-105KG were 0.20 +/- 0.02 and 0.03 +/- 0.01, respectively. Positive genetic correlations were estimated between IGFI-8W and DG (0.26 +/- 0.08), EM (0.22 +/- 0.10), and IMF (0.32 +/- 0.10). Moreover, the positive genetic correlation between IGFI-105KG and EM was 0.42 +/- 0.08. These results indicate that serum IGF-I concentration at an early stage of growth was effective for prediction of IMF, but it was not a reliable physiological predictor of genetic merit of meat production traits.
本研究旨在探讨血清胰岛素样生长因子-I（IGF-I）浓度是否适合作为猪产肉性能和肉质性状遗传改良的生理预测指标。对这些性状的遗传力和遗传相关性进行了估计。本研究中使用的杜洛克猪品种针对体重30至105千克期间的平均日增重（DG）、眼肌面积（EM）、背膘厚度（BF）和肌内脂肪（IMF）含量进行了七代选育。对832头动物在第4代选育时的公猪和后备母猪以及第5至7代选育时的公猪、后备母猪和阉公猪在8周龄时（IGFI-8W）测定血清IGF-I浓度，对834头动物在体重达到105千克时（IGFI-105KG）再次测定血清IGF-I浓度。采用多变量限制最大似然法（REML），通过包含选育世代、性别、同窝仔猪的共同环境效应和个体加性遗传效应的模型来估计遗传参数。IGFI-8W和IGFI-105KG的遗传力估计值分别为0.23±0.02和0.26±0.03。IGFI-8W和IGFI-105KG的共同环境效应估计值分别为0.20±0.02和0.03±0.01。估计IGFI-8W与DG（0.26±0.08）、EM（0.22±0.10）和IMF（0.32±0.10）之间存在正遗传相关性。此外，IGFI-105KG与EM之间的正遗传相关性为0.42±0.08。这些结果表明，生长早期的血清IGF-I浓度对IMF的预测有效，但它不是产肉性状遗传价值的可靠生理预测指标。
