Seasonal variation in the reproductive activity of male goats raised under tropical climate conditions

Abstract

This study analyzed seasonal variations in the testes, the concentration of sex hormones, the parameters of fresh and thawed semen, and the sexual behavior of male Alpine goats from a temperate region in a tropical climate and possible interference with fertility. The maximum and minimum temperature and luminosity were recorded daily, while seminal, hormonal, and behavioral assessments were carried out every fortnight. The maximum and minimum temperature (°C) and luminosity (h) were recorded daily always at 17.00 h. The scrotal circumference (cm), testicular volume (mL), volume (mL), appearance (creamy, milky, aqueous) and coloration (white, white-yellowish, and yellowish) seminal, turbulence or mass movement (0 to 5), progressive spermatic motility (0 to 100%), spermatic force (0 to 5), concentration (spermatozoids/mL), spermatic pathologies, hypoosmotic test (%), serum levels of FSH (mUI/mL), LH (mUI/mL), testosterone (ng/mL), and sexual behaviors were carried out every fortnight. There was a difference between the scrotal circumference evaluated monthly, testicular volume, volume and concentration of fresh semen, sperm vigor of the thawed semen, serum levels of testosterone, FSH and LH, and some sexual behaviors. Thus, the changes that occur in the quantity and quality of sperm, in the hormonal profile, and in sexual behaviors should not be regarded as an impediment to the use of male Alpine goats in tropical climates throughout the year. These variations do not lead to changes in the semen that may compromise the fertility of these animals.