reduced fertility in the rooster
- Avian Diseases
A study on the occurrence of epididymal lithiasis (EL) in Gallus gallus domesticus of different breeds and from different geographical regions of Brazil was carried out. Forty breeding roosters were collected in the states Santa Catarina, São Paulo, Minas Gerais, Espírito Santo and Goiás, representing two specific pathogen free Leghorn lines (SPF), one commercial Leghorn layer breeder (Hy-Line) line, two commercial broiler breeder lines (Ross and Cobb), and two backyard chicken flocks. In commercial poultry breeders, EL was observed mainly after 55 weeks of age, and lithus resulted in lower fertility caused by inadequate maturation of spermatozoa and testicular atrophy, which evolved to more severe testicular dysfunction at 100 weeks of age. One hundred percent of the sampled roosters of the evaluated SPF lines presented epididymal lithiasis, which was also observed in all commercial genetic lines. The analysis of EL occurrence revealed no differences among regions and breeds: all regions and genetic lines presented epididymal calculi and the occurrence seemed higher in the more intensively-reared chickens. As for the backyard roosters, 50% presented calculi. Considering the occurrence of EL in the SPF flocks, its primary association with infectious bronchitis virus (IBV) infection was discarded, despite its contribution to fertility loss.