Genetic analysis of production traits for improvement of national beef cattle genetic evaluations: Mature weight, body condition score, hip height, birth weight, and weaning weight

National beef cattle genetic evaluations must be complete and accurate in order to have the greatest impact on selection. Improvements can be accomplished through addition of traits that will aid in selection for economically relevant traits and by more accurate analysis of traits currently included in genetic evaluations. Genetic parameters were estimated for mature weight, body condition score, and mature hip height using records from one control and three selection lines of Hereford cattle; these traits are not routinely included in genetic evaluations. Estimates of heritability were 0.75 (0.11), 0.63 (0.09), 0.16 (0.04), 0.48 (0.04) for mature weight, mature weight adjusted for body condition score, body condition score, and mature hip height, respectively. Parameters for weaning and yearling hip height were estimated using field data from the North American Limousin Foundation. Estimates of heritability were 0.36 (0.02) and 0.43 (0.02) for weaning and yearling hip height, respectively. Age-of-dam adjustment factors were evaluated for birth and weaning weight using field data from the Red Angus Association of America. Birth weight adjustments for bull calves were calculated to be 3.13, 1.41, 0.41, and 1.13 kg for dams that were 2, 3, 4, and 11 yr of age and older when set to a mature cow basis of 5 to 10 years of age. Birth weight adjustments for heifer calves were 3.08, 1.32, 0.45, and 1.04 kg, for the same age groups, respectively. For weaning weight, adjustments were calculated to be 32.97, 17.19, 7.30, and 11.97 kg for bull calves and 25.80, 13.70, 4.90, and 10.48 kg, for heifer calves for the same age-of-dam groupings, respectively. Mature weight, body condition score, and hip height can be included in genetic evaluations to aid producers in selection decisions. More appropriate estimates of age-of-dam adjustment factors for birth and weaning weight will improve prediction of breeding values for these traits.