Objective: This work was designed to compare testicular parameters of Isa- brown cockerel from two climates in Nigeria. A total of twelve Isa-brown cockerels of 18-24 months weighing between 3-4 kg were used. Six cockerels were randomly selected from three breeder farms inJos (group A)while six were from Gwagwalada (group B) during the dry season. Methods: The twelve cockerels were assembled at the University of Abuja Permanent site for the study. The cockerels were acclimatized for two weeks after which they were weighed and sacrificed by method of cervical dislocation and the testes and pituitary glands were dissected out. The weight of the organs were measured with a sensitive scale. Testicular length and width were measured with a measuring tape. Results: Results showed that values of the testicular parameters were higher in the left testes compared to the right testes. Testicular width and weight of the cockerels were higher in Jos. The group A showed left testicular length, width and weight of 3.98±0.24cm,1.83±0.17cm, 8.38±2.21g while B showed values of 3.15±0.33cm, 1.42±0.22cm, 8.00±1.60g respectively (p>0.05). The right testicular parameters were 3.52±0.30 cm, 1.75±0.14cm,7.28±1.90g for group A, while group B showed values of 3.87±0.48cm, 1.37±0.23cm, 6.77±1.46g respectively (P>0.05). The mean body weight for groups A and B were 3.50± 1.21 kg and 3.47± 0.15kg respectively. (P>0.05), Weight of pituitary gland for both groups were3.90±0.21g and 4.64±0.80g respectively (p>0.05). Conclusion: It was concluded that group B may have been exposed to heat stress resulting in lower testicular width and weight.It was recommended that caution be exercised in establishing commercial breeder farms in Gwagwalada area of Abuja. Further studies should be done to unravel more comfortable zones in Abuja for breeder farm operations.
