Phenotypic and genetic relationships of residual feed intake measures and their component traits with fatty acid composition in subcutaneous adipose of beef cattle

摘要: Feed efficiency is of particular interest to the beef industry because feed largest variable cost in production and fatty acid composition emerging as an important trait, both economically socially, due potential implications dietary acids on human health. Quantifying correlations between will contribute construction optimal multiple-trait selection indexes maximize profitability. In present study, we estimated phenotypic genetic measures including residual intake (RFI), RFI adjusted for final ultrasound backfat thickness (RFIf); their component traits ADG, DMI, metabolic BW; measured at end feedlot test with 25 major subcutaneous adipose tissues 1,366 finishing steers heifers using bivariate animal models. The RFIf individual grouped were generally low (<0.25 magnitude). However, relatively stronger correlation coefficients PUFA -6:-3 ratio (0.52 ± 0.29 0.45 0.31, respectively), 18:2-6 (0.45 0.18 0.40 0.19, -6 (0.43 0.38 (0.42 0.36 0.20, 9-16:1 (-0.43 0.20 -0.33 0.22, respectively) observed. Hence, low-RFI or more efficient cattle improve profiles by lowering content PUFA, thus reducing -3 along increasing amount 9-16:1. Moderate moderately high also observed DMI 9-14:1 (-0.32 0.17) sum CLA analyzed (SumCLA; -0.45 0.21), suggesting that lower lead increase SumCLA tissue. unfavorable detected ADG 11-18:1 (-0.38 0.23) (-0.73 0.26), implying a better growth rate decrease contents healthy SumCLA. Therefore, it recommended index be used when improvements composition, efficiency, intake, are breeding objective.