Avaliação dos diferentes níveis de feno de alfafa sobre parâmetros morfométricos e qualitativos do parênquima testicular e níveis séricos de testosterona em ovinos (Ovis aries) sem raça definida.

Abstract

Aiming to evaluate the different levels of alfalfa hay on morphometric and qualitative parameters of the testicular parenchyma and serum testosterone levels in sheep (Ovisaries) of mixed breeds, 40 sheep were used in growth, with average body weight of 26 ± 1.85 kg to approximately eight months of age. The animals were subjected to 100 days confinement (with 44 days for adaptation to management and 56 days for the administration of the experimental diets). The treatments consisted of four levels of alfalfa hay: 0%, 20%, 40% and 60%, so was maintained proportion of 60% forage for all diets. At the end of the experiment, blood collection was performed for serum testosterone measurement and weighing of animals. After slaughter, the complex testicle-epididymis were removed and individually weighed, after we calculated the GSI. Histological sections were obtained (4 mm) of testicle, which were stained with hematoxylin-Phloxine and Toluidine Blue, mounted with entelan and analyzed morphologically and morphometrically in optical microscope. The body weight, scrotal circumference and IGS showed no statistical difference neither regression effect. Among the tubular parameters, height and epithelium area suffered decreasing linear effect. The volumetric ratio, the tunic, the individual volumes and the total Leydig cells as well as blood vessels suffered increasing linear regression effect. In sperm production there was also much effect regression as statistical difference, besides the regression suffered by the rounded number of spermatids per section. Thus, it was concluded that the inclusion of alfalfa a ratio above 20% is not recommended for breeding sheep because it compromises the testicular parenchyma.