Effects of phenotypic selection for residual feed intake on growth performance and carcass traits in Angus- and Braunvieh-sired cattle
Murray, Patrick Tyler
MetadataShow full item record
The impact of RFI selection was investigated using offspring (n=67) from commercial Angus cows mated to Angus (AA) or Braunvieh (BA) bulls with large differences in RFI (high vs low). Following slaughter at predetermined endpoints of 1.4 cm for AA and 1.0 cm for BA, carcass data were collected and slice shear force was performed. Low RFI cattle gained faster, were heavier at slaughter, and tended to have higher G:F than high RFI. BA cattle were heavier entering the feedlot and spent longer on feed with lower G:F than AA. Breed nor RFI selection impacted RFI. Carcasses from low RFI sires were heavier with larger REA and lower USDA yield grades. Total primal yield (%) was higher in BA vs AA, low RFI vs high, and steers vs heifers. Findings suggest that selection using phenotypic RFI in bulls had no effect on RFI in their first generation calves, although certain measures of growth and efficiency were improved.