Tasa de fertilidad al primer servicio en vacas resultantes del cruce alterno entre Brahman Rojo y Holstein Rojo de acuerdo con el predominio racial, la generación (madres e hijas) y a la época de parto

Abstract

The fertility rate at 1st service (FPS) is the percentage relationship between the cows that become pregnant at the 1st service and those that are served for the first time, and constitutes an important reproductive index that allows evaluating the reproductive efficiency of the herd (González-Stagnaro, 2001). The effect of racial predominance and season on FPS in tropical mestizo cows was previously described (Perea et al., 2005; Perea and González-Stagnaro, 2005). In Bos indicus predominant cows, FPS is higher than in Bos taurus predominant cows (Perea et al., 2006). The dry season favors a higher FPS in both genetic groups (Perea et al., 2006). Considering a population of mestizo cows subject to alternate crossbreeding between the Red Holstein and Red Brahman breeds, the objective of this study was to evaluate the FPS in predominantly Brahman or Holstein mothers and daughters according to three calving seasons in the year.