Sperm morphological attributes in indigenous male goats raised under extensive husbandry in Ethiopia
Anim Reprod, vol.4, n1, p.15-22, 2007
This study assessed the morphological attributes of epididymal spermatozoa from indigenous goat breeds managed under conditions of extensive husbandry in Ethiopia. Seventy-four healthy male goats from 5 breeds (Arsi-Bale [AB], Afar, Central Highlands [CH], Boran, and Woito-Guji [WG]) and 3 age groups (< 14 mo [younger]; 14.0 – 19.5 mo [intermediate]; 19.6 – 24 mo [older]) were randomly selected, and their epididymal spermatozoa were evaluated for morphology. While in caput and corpus, the proportion of detached heads, proximal droplets, abnormal midpieces, and simple bent tails were greatest (P < 0.05). Simple bent tails were lowest in the cauda epididymides whereas inversely the proportion of distal droplets and coiled tail defects was greatest (P < 0.05) in the cauda. In the cauda epididymides, defective acrosomes were greatest (P < 0.05) for CH goats and the least for Boran and WG. The proportion of loose sperm heads was greatest (P < 0.05) for AB. The occurrence of narrow and variable-sized spermatozoa was greater (P < 0.05) for lowland (Afar, Boran, and WG) than highland (AB, CH) goat breeds. Afar and CH goats had more (P < 0.05) coiled tails than the rest of the goat breeds. Indigenous goats at a younger age had an increased (P < 0.05) proportion of loose heads while those in the older age group had a greater (P < 0.05) proportion of acrosome defects. Older goats also had an increased (P < 0.05) proportion of distal droplets and tail defects compared to goats at a younger age. In conclusion, while sperm-head morphological abnormalities were not severely influenced by breed and age group, these variables affected proportions of loose sperm heads and acrosome defects.
sperm morphology; tropical male goats; age; breed; epididymis