TY  - JOUR
T1  - Comparison of Crossbred Heifers Mated Naturally to Red Poll Bulls for Production and Growth Traits
AU - , A.P. Marquez AU - , H. Gonzalez-Garcia 
JO  - Journal of Animal and Veterinary Advances
VL  - 7
IS  - 4
SP  - 485
EP  - 488
PY  - 2008
DA  - 2001/08/19
SN  - 1680-5593
DO  - javaa.2008.485.488
UR  - https://makhillpublications.co/view-article.php?doi=javaa.2008.485.488
KW  - Crossbred cows
KW  -birth weight
KW  -weaning weight
KW  -calving difficulty
KW  -survival
AB  - Crossbred dams when mated at different ages and in different years by natural service to Red Poll (n = 415) were compared for calf birth weight BW, weaning weight WW, calving difficulty CD measured categorically  and  calving  ease CE  measured binomially and calf survival CS. 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. Red Poll sired cows had more calving difficulty; but were heavier at birth and weaning weight. Heifer calves had less calving  difficulty  than bull calves. There were few differences among dam breeds for survival at weaning, at 3rd day or at birth.
ER  -