GM 10. Factors affecting survival up to 12 months in a dual purpose herd

Abstract

In order to study calf survival up to 12 month, as well as non genetics factors and breed group which affect then, 14951 records from a dual purpose farm were used. All animals grazed introduced pastures without supplementation. All cows were hand milked with their calves up to 8-12 months of age. 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:1987-1995), month of birth (M), age of dam (1-6 calving), age of calf (days) and birth weigth (kg) as covariables, and the interaction of AxM, AxGR, MxGR. All the variables were analized by completly randomized model. The adjusted average was 73.4 ± 0.29 %, inferior to the expected values in the literature, indicating the need to establish corrective measures in the management of calves after parturition. All the variables were significants (P<.01). Year of birth, sex and age of calf, explained the grater part of variation. A increased on survival in the years of studied was observed. Males outlived the females. The last 5 months of the year had the highest survival time. Claves from primiparous cows had the highest survival.