Animal Science Department


Date of this Version



Proceedings, 10th World Congress of Genetics Applied to Livestock Production


Copyright © 2012 American Registry of Professional Animal Scientists. Used by permission.


Heterosis, assumed proportional to expected breed heterozygosity, was calculated for 4,835 individuals with birth, weaning and yearling weight records from Cycle VII of the U.S. Meat Animal Research Center Germplasm Evaluation Program. Heterosis was further estimated by proportions of British x British (BxB), British x Continental (BxC) and Continental x Continental (CxC) crosses. Angus and Red Angus were considered a single breed for estimation of heterosis. Direct heritability estimates (SE) for birth, weaning and yearling weight were 0.39 (0.05), 0.18 (0.04) and .40 (0.06), respectively. The BxB covariate was significant and BxC approached significance for weaning weight. The BxB proportion was significant for yearling weight. Heterosis in BxB tended to be higher at yearling than CxC and BxC.