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.


Birth weight (BWT) and calving difficulty (CD) were recorded on 4,580 first parity females from the Germplasm Evaluation (GPE) program at the U.S. Meat Animal Research Center. Both traits were analyzed using a bivariate animal model with direct and maternal effects. Genetic groups for breed of AI sire were fitted to estimate breed differences. Bos Indicus influenced breeds tended to have the largest BWT. Heritability estimates for BWT direct, CD direct, BWT maternal and CD maternal were 0.45 (0.09), 0.40 (0.09), 0.18 (0.08), and 0.18 (0.08), respectively. Genetic correlation estimates were positive between direct BWT and CD direct at 0.82 (0.10). All other genetic correlations were not significant.