Effect of holding and washing on the quality of goat semen

A total of 18 pooled semen samples collected from 4 healthy crossbred (Beetal × Assam Local) bucks, twice weekly for a period of 12 weeks, were processed via three processing methods, viz. Method I (holding after washing: semen sample was washed twice, extended, held for 0, 1, 3 and 5 h and preserved), Method II (washing after holding: semen sample held for 0, 1, 3 and 5 h, washed twice, extended and preserved) and Method III (holding of undiluted semen: semen sample held for 0, 1, 3 and 5 h, extended and preserved). An isotonic Tris buffer was used to wash the spermatozoa with the aid of centrifugation at 3000 rotations per minute (rpm) for 10 min. A Tris-citric acid-fructose-egg yolk extender was used to extend the semen processed with all three processing methods and preserved at 5 °C up to 72 h. Holding of semen at 24 °C in each processing method caused deterioration of the semen quality during preservation, as the holding time increased from 0 (without holding), 1, 3 and 5 h. The initial sperm motility declined from 85.8 to 71.7% in Method I, from 85.8 to 21.7% in Method II and from 84.2 to 45.0% in Method III, as the holding time increased from 0 to 5 h. The corresponding values were 66.7 and 49.2% for Method I, 66.7 and 8.0% for Method II and 42.5 and 25.8% for Method III, following 72 h of preservation. The percentage of live sperm and intact acrosomes also showed a similar decreasing trend as the holding time increased from 0 to 5 h in all processing methods as revealed in percentage of sperm motility. Washing of spermatozoa without a holding period maintained significantly higher sperm motility (66.7%), live sperm counts (83.0%) and incidence of intact acrosomes (79.3%) following 72 h at preservation, compared to the corresponding values (42.5, 65.2 and 73.3% for sperm motility, live sperm counts and intact acrosomes, respectively) recorded in unwashed semen without a holding period. The values recorded for washed semen without holding were also significantly higher than for semen held for 1, 3 and 5 h in all the three processing methods following 72 h of preservation. This study revealed that the holding of semen caused deterioration of the spermatozoa, whereas, washing without holding had a beneficial effect on the viability of spermatozoa in maintaining its storage ability for up to 72 h of preservation at refrigeration temperature (5 °C).