Relationship Between Maternal Factors, Colostrum Quality, and Weaning Weight Performance in Holstein Calves in High Andean Systems in Ecuador

Bovine colostrum quality plays a crucial role in the passive transfer of immunity and the early growth of calves. This research investigated how maternal factors, colostrum Brix percentage, and additional variables are associated with calf weaning weight in 34 Holstein in an altitude system in Tulcán, Ecuador. Colostrum samples were collected in the first two hours postpartum and analysed by digital refractometry. Non-parametric analysis and multiple linear regression were applied. 82.4% of the samples were classified as good quality. Surprisingly, a negative correlation was found between % Brix and weaning weight (ρ = -0.40, p = 0.02). Parity was significantly associated with colostrum quality (p = 0.0496). The regression model explained 84% of the variability in weaning weights, with birth weight, cow weight, and colostrum quality being significant. These results highlight the need for comprehensive colostrum evaluation beyond % Brix.