Some Risk Factors Of Early Loss And Longevity Of Beef Cows

Background: Longevity of a beef cow, defined as length of productive life from first calving to culling is a complex trait of great importance as it reflects the performance of her total herd life. Longer productive life may increase profits by decreasing annual costs of replacement cows associated with raising breeding heifers.Objectives: The aim of this study was to estimate the risk factors of early loss and the longevity of beef cows kept in Hungary.Materials and Methods: Data from 1,800 cows belonging to Hereford, Angus, Simmental, Charolais, Limousin and Blonde d' Aquitaine breeds bred in different herds were estimated. Proportional Hazard (PH) model based on Cox regression was used for data processing. The model is part of SPSS 14.0 software.Results and Discussion: Breed, calving season and calving difficulty had significant effect on longevity (p < 0.05); however herd, age of the cow at first calving, sex and weaning weight of their calves did not affect (p > 0.05) the risk and length of productive life. Hereford had significantly longer (9.3 years) estimated longevity than Angus (8.1 years), Simmental (7.9 years), Charolais (7.1 years), Limousin (5.9 years) and Blonde d' Aquitaine (5.2 years). Cows that calved first in spring or summer were estimated to have longer productive life (7.2 years and 6.9 years) and less risk of early culling than those calving in autumn (5.7 years) and in winter (5.1 years). Longer productive life (6.2 years) was estimated for cows calving without assistance or with a little assistance (6.9 years) compared to than those needing veterinary assistance (2.8 years) or having stillbirth (4.6 years).Conclusion: Because longevity is a complex trait of great economic importance, special attention should be devoted to these risk factors. By using sire breeds with easy calving genetic background and organizing calving in spring or summer, longer productive life and less risk of early cow's loss can be expected.y