In this sense, a large body of data indicates that reproductive aging in roosters can affect both semen quality and sexual behavior through the following mechanisms: overweighting, testicular atrophy, epididymal lithiasis, compromised antioxidant system, reduced number of GnRH-I producing cells, reduced testicular LH and FSH receptors and reduced plasma FSH and testosterone concentrations (Ansari, 2024). The gene discussed is FSHR; the disease is Testicular atrophy.