GM 11. Factors affecting survival between 12 and 24 months in a dual purpose herd

Abstract

In order to study calf survival between 12 and 24 months of age, as well as non-genetics factors and breed groups that affect then, 14951 records from a dual purpose farm were used. All animals grazed introduced pastures without supplementation. Animals between 12 and 24 months of age are placed in 2 herds and separated according to sex. The health plan included vaccinations and periodic check-ups for endo and ectoparasites. The factors studied were: breed group (GR: 1= Santa Gertrudis (SG); 2= high-grade SG; 3= SG x Bos taurus), sex, year of birth (A:1987-1994), month of birth (M), age of dam (1-6 calving), age of calf (days) and birth weight (kg) as covariables, and the interaction of AxM, AxGR, MxGR. All the variables were analyzed by a completely randomized model. The adjusted average was 79.9 ± 0.28 %, inferior to the expected values in the literature, indicating the need to establish corrective measures in the management of calves after weaning. All the variables were significant (P< 0.01). Year of birth, sex and age of calf, explained the greater part of the variation. An increase in survival in the years of study was observed. Males outlived females. The last 5 months of the year had the highest survival time. Calves from primiparous cows had the highest survival time.