Abstract
Field data were collected on Beefmaster cattle from three central Texas ranches and three Beefmaster auction sales. Statistical analysis was performed on these data to evaluate the effects of: year, herd, sire, sex of calf, season of birth and sex x season interaction on 205d, age of dam adjusted, weaning weight and calf sheath/navel score. Further analysis was performed to evaluate the effects of herd, sex of calf, dam navel score, sire sheath score, dam navel x sire sheath and adjusted weaning weight on calf sheath/navel score. The sale data was analyzed to evaluate the effects of sheath score on sale price. The effect of sires was nested within herd and herd was nested within year. The effects of herd, sire within herd and sex of calf were significant for adjusted weaning weight (P <.001). Bull calves were heavier at weaning than heifer calves. Calf sheath/navel score was significant for adjusted weaning weight (P <.05). Calves scoring three for sheath/navel were heavier than those scoring two or less, but were not different than calves scoring four or greater. The effects of herd, sex of calf, dam navel score, sire sheath score, dam navel x sire sheath interaction and adjusted weaning weight were significant for calf sheath/navel score. Bull calves had higher sheath/navel scores than heifer calves (P <.01). Calf sheath/navel score increased significantly with both dam navel score (P <.01) and sire sheath score (P <.001). The dam navel x sire sheath interaction was significant for calf sheath/navel score (P <.05). The magnitude of the differences in mean calf sheath/navel score for the three sire sheath scores are greater for dam navel scores two or less and four or greater than for dam navel score three. Adjusted weaning weight was also significant for calf sheath/navel score. Heavier calves tended to have higher sheath/navel scores (more pendulous) than lighter calves. The heritability estimate of calf sheath/navel score was.55 [plus or minus] .07. Both genetic and phenotypic correlations between calf sheath/navel score and adjusted weaning weight were near zero. Sheath score did not appear to have a significant effect on the sale price of Beefmaster bulls.
McMurry, Bryan (1990). Association of sheath and navel score with growth and sale price in Beefmaster cattle. Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -1163167.