Genomic prediction ability and genetic parameters for residual feed intake calculated using different approaches and their associations with growth, reproductive, and carcass traits in Nellore cattle

This study aimed to estimate prediction ability and genetic parameters for residual feed intake ( RFI ) calculated using a regression equation for each test ( RFI test ) and for the whole population ( RFI pop ) in Nellore beef cattle. It also aimed to evaluate the correlations between RFI pop and RFI test with growth, reproductive, and carcass traits. Genotypic and phenotypic records from 8354 animals were used. An analysis of variance (ANOVA) was performed to verify the adequacy of the regression equations applied to estimate the RFI test and RFI pop . The (co)variance components were obtained using the single-step genomic best linear unbiased prediction under single and two-trait animal model analyses. The genetic and phenotypic correlations between RFI test and RFI pop with dry matter intake, frame, growth, reproduction, and carcass-related traits were evaluated. The prediction ability and bias were estimated to compare the RFI test and RFI pop genomic breeding values ( GEBV ). The RFI pop ANOVA showed a higher significance level ( p