RISK FACTORS ASSOCIATED WITH ABORTION AND CALF PREWEANING MORTALITY IN A BEEF CATTLE SYSTEM IN SOUTHEASTERN MEXICO

Abstract

Data from 2438 calvings born to 682 cows recorded from 2004 to 2015 in an extensive production system were used, to investigate factors associated with abortion and calf mortality until weaning. Cows belonged to Brahman, Nellore, Guzerat and Brown Swiss x Zebu breed groups. Data were analyzed using binary logistic regression, and the statistical model included the effects of year and season of calving (or abortion), parity number, breed group of the cow and sex (only for preweaning mortality). Abortion rate was 0.99% varying from 0.61% to 1.94% among year groups. First parity and Nellore cows had the greatest abortion rates (1.66 and 1.46%, respectively). The calf mortality rate was 9.65%, varying from 3.18% to 14.65% across all years. The major factors associated (P < 0.05) with mortality of calves included year and season of calving, parity number and breed group of the cow. Nellore cows had the highest odds of preweaning mortality (OR=4.41). Cow parity number and season of calving were also associated with calf mortality. First parity cows had the major calf losses overall. In conclusion, closer attention to the management of first parity cows could reduce calf mortality.