ABSTRACT The present study sought to examine the effects of low-protein diets supplemented with natural and synthetic antioxidants on reproductive traits and performance of male Japanese quail. A total of 144 one-day-old quail chicks were randomly assigned to receive four different treatments, including a control diet (a basal diet) without antioxidant supplementation, low-protein diet without antioxidant supplementation, low-protein diet supplemented with the E-selenium antioxidant (a combination of vitamin E and selenium), and low-protein diet supplemented with the antioxidant Loxidan (a […]

Testosterone levels to the body weight, relative and absolute testes weights, tunica albuginea thickness, germinative epithelium height, diameter and meiosis picture numbers of seminiferous tubules of 65 male quails were evaluated from June to October. The birds were grouped in cages (6 birds/cage) and lodged in a shed during all experimental period. The testis morphometric analysis was carried out from 60 days to 180 days old. The total testosterone plasmatic levels were dosed by radioimmunoassay method with antibody radioactivity marked. […]

This study aimed to evaluate changes in hormone secretion and in seminiferous epithelium of Angus bulls between 10 and 38 weeks of age. Samples of testicular parenchyma and blood were collected from 25 animals castrated in 4 week intervals. Traits associated to testicular development and quantitative aspects of spermatogenesis and hormonal concentrations were transformed by logarithm before analyses of variance. Changes in testis and seminiferous tubule diameter and testis weight were more pronounced after 26 weeks of age. The percentage […]

A study was conducted to determine the effect of heat stress on semen criteria and testis size in Santa Inês hairy rams, in the State of Ceará, Northeast of Brazil. The scrotum of eight adult rams was insulated for seven days. Animals were evaluated twice before insulation and, after insulation, at 12 different periods until 118 days. Scrotal insulation did not affect semen volume, but pH was increased after eight days, returning to normal values after 15 days. Sperm concentration […]

The objective of this research was to determine the correlation among hormone levels at 2- and 6-month of age and diameter and histology of the testis in Angus x Charolais young bulls at 6 months (n= 15). At two months, two basal blood samples were collected at 1-h intervals. After the last collection, the animals received 5 mg of GnRH and 1.5 and 3.0 h later, new samples were collected. At 6 months, the young bulls were treated with 1 […]