Reproductive evaluation of Charolais and Charbray bulls on the reproductive efficiency of herds in the humid tropics of Veracruz

Abstract

Objective: To analyze the breeding soundness examination (BSE) of the Charolais and Charbray breeds in the humid tropics on the efficiency of herds to determine differences between breeds. Design / methodology / approach: Results of the BSE of N = 90 Bulls, Charolais (n = 33) and Charbray (n = 57) breeds, evaluated in situ during the years, 2017-2019. Bull (age, body condition score, libido and scrotal circumference), semen (concentration, motility and volume), herd (pregnancy rate and calve interval) and environmental variables (season: dry and rainy) were analyzed with ANOVA One-Way, factorial, multiple regression and multivariate analyses, using STATISTICA v10 software. Results: Charolais and Charbray bulls show similar results in BSE (p> 0.05) in tropical environmental conditions. Limitations / implications: Seasons and do not affect (p <0.05) the BSE. Libido, a variable not systematically included in the BSE is associated (p <0.05) with age (R = -0.42), motility (R = 0.67), sperm concentration (R = 0.66) pregnancy rate (R = 0.63) and clave interval (R= -0.33). Findings / conclusions: Variables with high association with the gestation rate were: age (R = -0.50), libido (R = 0.63), motility (R = 0.60) and sperm concentration (R = 0.51). Variables with high association (p <0.05) with the calve interval were: age (R = 0.74) and libido (R = -0.33). The environmental variables did not affect the ECR of the Charolais and Charbray bulls in a different way.