F. UGUR1, M. MENDES1, M. YANAR2 and A. PALA1
1 Canakkale Onsekiz Mart University, Faculty of Agriculture, Animal Science Department, 17020 Canakkale, Turkey
2 Ataturk University, Faculty of Agriculture, Animal Science Department, 25240 Erzurum, Turkey
UGUR, F., M. MENDES, M. YANAR and A. PALA, 2004. Performances of dairy heifers weaned at 30, 45 and 60 days of age. Bulg. J. Agric. Sci., 10: 515-517
The effects of early weaning on age at first calving on the milk and milk fat yield characteristics of Brown Swiss and Holstein-Friesian cattle were studied. The calves used in this study were weaned at 30, 45 and 60 days of age. The differences among the weaning groups concerning age at first calving, 305- day milk yield, the percentage of milk fat and 305 - day milk fat yield were found to be insignificant (P>0.05). The results of this study suggested that early weaning of Brown Swiss and Holstein Friesian calves at 30 days of age would not have a detrimental effect on age at first calving and milk production traits.