Sperm production rate, gonadal and extragonadal sperm reserves in slaughtered White Fulani (Bunaji) bulls in a lowland tropical environment

Résumé

Reproductive tract morphometry, sperm production rates, gonadal and extragonadal sperm reserves in Bunaji bulls were evaluated using samples from a total of 13 mature animals. The morphometric characteristics of the reproductive organs had generally low values but showed normal development. The daily sperm production (DSP) averaged 1.23 ± 0.16 x 10⁹, while the daily sperm production (DSG/g) was 0.62 ± 0.11 x 10⁷. Gonadal sperm reserve was 2.17 ± 0.73 x 10⁹ while extragonadal sperm reserve was 3.82 x 10⁹ for caput, 2.68 x 10⁹ for corpus, 4.36 x 10 (for cauda epididymis and 0.62 x 10⁹ for the ductus deferens. The relative contributions of the epididymal segments and the ductus deferns to the total extragonadal sperm reserves were 33.28%, 23.34%, 37.98% and 5.40% respectively. Testicular morphomeric characteristics correlated highly with themselves and with sperm production parameters as well as extragonadal sperm reserve. While these results provided information that would be useful in the determination if male/female ratio during mating and artificial insemination programmmes, the study also shows that good sires could be obtained from these animals for breeding and improvement programmes in this breed.