Live weight related changes in the sperm production capacity of white fulani (Bos indicus) cattle I: testicular histomorphometry.
The study investigated live weight related changes in testicular histomorphmery of White Fulani (WF) bulls of live weight range 171-320 kg under the traditional extensive system of management in Ibadan, Nigeria. Fifty-two WF bulls were randomly selected from local Fulani herds around Ibadan and placed in Giant Star grass paddocks with water available free choice for one week prior to slaughter. Morhpometric measurements were taken on the scrotum before and on the testes immediately after slaughter. Histometric measurements were taken on the testicular parenchyma tissue after histological processes. From their weight at slaughter, the bulls were grouped into four live weight groups of 171-200, 201-230, 231-260 and 261-320 kg for group I, II, III and IV, respectively. Mean values of group IV bulls were significantly (p<0.05) higher in all scrotal and testicular morphometric measurements than all other groups, which did not differ significantly (p>0.05) from one another. The gonadal index (relative weight of testes to live weight) did not differ (p>0.05) between groups except that group IV value was significantly (p<0.05) higher than all other groups. The relative proportion of paired epididymal weight to live weight did not differ between groups, while the relative proportion of tunica albuginea to the testes weight decreased insignificantly from group I to IV. The seminiferous tubule diameter did not significantly (p>0.05) differ between groups, while the stages in the cycle of the seminiferous epithelium also appeared stable between the different live weight groups. The volume proportion of the lumen in the semiferuos epithelium was significantly higher in group I bulls than group IV bulls while none of the testicular elements differed significantly (p>0.05) between groups in volume proportions. However, absolute weights of all the testicular elements were significantly higher in the group IV bulls than all the other groups, which did not differ significantly (p>0.05) from one another. It was concluded that the live weight range 171-320 kg corresponds to a physiologically stable state in White Fulani bulls extensively managed in Ibadan, a humid tropical environment in Nigeria.
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Department of Animal Production and Health, Faculty of Agricultural Sciences, Ladoke Akintola University of Technology, Ogbomoso, Oyo State, Nigeria.
D000818:Animals; D001835:Body Weight; D002417:Cattle; D008297:Male; D009549:Nigeria; D009929:Organ Size; D012611:Scrotum / Q000033:anatomy & histology; D013094:Spermatozoa / Q000378:metabolism*; D013737:Testis / Q000033:anatomy & histology*; D014329:Tropical Climate