Semen characteristics, morphology and testicular parameters of Uda (ovis aries) in Ibadan, Nigeria

The spermiogram and biometrical observations on the testes and epididymis of 20 adult Uda rams were investigated. The study was aimed at providing information on the reproductive potentials of Uda rams in Ibadan, and thus improved evaluation of breeding soundness in rams. The average age of the rams was 26.40±7.39 months, and their mean body weight was 39.80±3.00kg. The lengths of the right testes (14.34±1.24) and epididymis (20.50±2.94) as well as the circumference of the right testes (19.08±2.46) were significantly higher than their left counterparts (12.86±2.49, 18.50±3.36 and 16.40±4.35, respectively). The longer testes had a higher number of sperm cell abnormalities (23.43±4.97) compared to the shorter testes (15.03±6.91). Progressively, decreasing number of abnormalities was observed from the testes down the length of the epididymis from the head to the tail. The sperm cell abnormality that occurred most was the curved tail while the rudimentary tail was the least observed. The age was positively and significantly correlated with the body weight (r= 0.59, P<0.01) as well as most of the right testicular and epididymal parameters. The right testicular and epididymal volume was positively correlated with sperm motility of right caput epididymis (r= 0.82, P<0.05), and some other spermiogram parameters than the left which did not show any positive correlation. In conclusion, higher correlation observed between age and testicular measurements than with body weight implies that age is an important factor for selection of the Uda breed of ram.