Abstract
Approximately 150,000 weaning weight records from the North American Limousin Foundation were analyzed by data sets to estimate the magnitude and importance of sire × breed of dam interaction. The data sets included 50% Limousin calves with Hereford or Angus dams, 75% Limousin calves with crossbred Limousin-Angus or Lifnousin-Hereford dams and both 50 and 75% Limousin calves of various breed (including Angus and Hereford) backgrounds. Five of nine data sets were analyzed directly for the interaction and three of the five analyses indicated a significant sire by breed of dam interaction. Analyses indicated a significant interaction between sire and breed of dam when the breed of dam class was made up of Hereford and Angus dams or crossbred Limousin and foundation dams. The interaction was not significant when the breed of dam class was made up of crossbred Limousin and Angus foundation dams or crossbred Limousin-Hereford and Limousin-Angus dams. The percentage of total variation accounted for by interaction ranged from .3 to 4.0. The sire component of variance accounted for 1.5 to 2.7% of the total variance. Residual mean squares ranged from 354.8 to 404.6 kilograms squared. Repeatability of sire progeny performance when the sires were mated to different breeds of dams ranged from .27 to .59. Genetic correlations of the sire's progeny performance when mated to dams of various breed composition ranged from .03 ± .32 to .90 ± .23. Rank and product-moment correlations for sire “Expected Progeny Differences” from independent data sets containing weaning records of 50 and 75% Limousin calves were .59 and .58, respectively. Values for sets which included 50% Hereford or Angus calves were .57 and .46, respectively. Copyright © 1979. American Society of Animal Science . Copyright 1979 by American Society of Animal Science.