Authors : A.P. Marquez and H. Gonzalez-Garcia
Abstract: Crossbred dams when mated at different ages and in different years by natural service to Simmental bulls were compared for calf birth weight, weaning weight, calving difficulty, measured categorically and calving ease measured, binomially and calf survival. Crossbred cows were from Angus, Hereford, Pinzgauer, Brahman, Sahiwal and Tarentaise crosses. The analytical model included: dam line (breed combination of dam) age of dam, sex and year as fixed effects, whereas julian birth day was a covariate. For analyses with back cross dams, covariates were included in the model for fractions of inheritance from each breed and fraction of complete heterosis of dams due to Bos taurus by Bos taurus, Bos taurus � Bos indicus, Bos indicus � Bos indicus crosses instead of breed combination of dam. Differences among crossbred dam groups were observed for birth and weaning weight and calving difficulty. Birth and weaning weights were less in female calves than bull calves. Crosses involving Brhaman and Sahiwal cows had least calving difficulty.
A.P. Marquez and H. Gonzalez-Garcia , 2008. Comparison of Crossbred Cows Mated Naturally to Produce Calves At 3-7 Years of Age to Simmental Sires for Production and Growth Traits. Journal of Animal and Veterinary Advances, 7: 489-492.