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Genomic selection for feed efficiency in beef cattle offers an opportunity to reduce feed costs and greenhouse gas (GHG) emissions while increasing profitability and environmental sustainability in beef production. Data from a selection experiment using three beef cattle populations maintained at the University of Alberta Roy Berg Kinsella Research Ranch namely, the Kinsella beef composite (KC - split into efficient and control lines), purebred Angus (AN), and purebred Charolais (CH) were analyzed following three years of selection (2013–2016) to obtain an evaluation of selection responses. Selection was carried out using multiple trait selection indexes based on molecular breeding values (MBVs). For the KC and AN population, a maternal profitability index (MPI) for improved feed efficiency, i.e. low residual feed intake (RFI), higher direct (DWWT) and maternal weaning weights (MWWT) was applied, while for the CH population a feedlot profitability index (FPI) for low RFI, low dry matter intake (DMI), higher average daily gain (ADG), greater carcass marbling (CMAR), greater hot carcass weight (HCW), increased lean meat yield (LMY), and increased average back fat thickness (AFAT) was applied. Across the three populations, average estimated breeding values (EBVs) obtained from a multivariate animal model showed significant differences at P |
