The Semen Characteristics of Pubertal West African Dwarf Bucks

Semen was collected twice weekly between 0800 and 0900 hours from 6 healthy pubertal West African Dwarf (WAD) bucks for three months by electrical stimulation, and later evaluated and compared with values from healthy adult bucks of the same breed. Apart from semen colour, which was similar between pubertal and adult bucks, adult bucks were significantly superior (p 0.05) to pubertal bucks in semen volume, mass activity, sperm progressive motility, sperm concentration, live sperm, total sperm/ejaculate and normal sperm morphology. In addition, pubertal buck semen also had significantly higher (p 0.05) incidences of abnormal and dead spermatozoa. The incidence of coiled tails was however similar (p 0.05) between the two age groups. The sperm concentration in the pubertal buck was highly significantly and positively correlated with total sperm/ejaculate (r = 0.72; p 0.001), while semen volume was significantly but negatively related to the total sperm/ejaculate (r = -0.37; p 0.05). Based on the findings of this study, it is concluded that pubertal buck semen, though inferior in quantity and quality to that of the adult, may be sparingly used for AI, and that good sires may be selected at puberty on the basis of the physical characteristics of their semen