Relação entre circunferência escrotal, libido, hormônios e características do sêmen em touros Brangus e Pardo-suíço

Abstract

Libido is an important component of a bull s breeding ability; however it is difficult to make as assessment of libido during a breeding soundness examination. It is best assessed in young bulls and scrotal circumference is favorably correlated with semen traits. Sixteen Brangus and eight Brown-Swiss bulls, with 36 months old, extensively managed were evaluated. The objective of this work is to study the relationship between scrotal circumference, libido, hormones and semen characteristics in Brangus and Brown-Swiss bulls. Bulls were divided into two experimental groups: group 1, with 16 bulls Brangus, and group 2, with 8 bulls Brown-Swiss, evaluated for sexual soundness using physical and morphological characteristics of semen, sexual behavior, testosterone and cortisol serum concentrations. There was a difference in the serum testosterone (P<0,05) and cortisol (P<0,01) concentrations between groups. No correlation (P>0,05) between libido, scrotal circumference, motility , concentration, testosterone and major defects were obtained. It was observed correlation among motility and mass movement (0,50; P<0,01), vigor and mass movement (0,58; P<0,01), libido and vigor (0,55; P<0,01), libido and cortisol (-0,41; P<0,05). In conclusion, were not correlations between libido and sperm quality, libido and scrotal circumference, libido and testosterone.