Effect of different extenders on recovery and storage of epididymal ram spermatozoa

Abstract

This experiment was conducted to determine effect of different extender on recovery and storage of epididymal ram spermatozoa. Testes were obtained from eight mature rams which were slaughtered at four different occasions, a pair in each session. Caudal epididymis was isolated and divided to four equal parts. Spermatozoa recovery from each part of the caudal epididymis was performed by milk (M), Tris (T), Tris plus caproic acid (T-C) and sodium citrate (S) extenders. Spermatozoa in each extender were divided into four parts and then the amount of 0 (E0), 5 (E5), 10 (E10) and 15% (E15) egg yolk were added. Samples were chilled to 4 °C and stored for 7 days. The evaluation of sperm motility, viability, membrane integrity and acrosome integrity were performed daily. The results showed that there was interaction between egg yolk and storage time and also egg yolk and extender on sperm motility (p < 0.05). Sperm motility was highest at 15 % egg yolk (25.6 %) on 7 d (p < 0.05). Sperm motility was higher in ME15 (57.8 %) and T-CE15 (62.3 %) than TE15 (53.4 %) and SE15 (41.9 %; p < 0.05). There was interaction among egg yolk, extender and storage time on acrosome integrity, membrane integrity and sperm viability (p < 0.05). On 7 d, there were no differences among ME15, T-CE15 and TE15 on sperm viability and membrane integrity. Acrosome integrity was higher in T-CE15 (75.25 %) than ME15 (62.5 %) on 7 d (p < 0.05). Therefore, Tris caproic extender was superior to other extender for recovery and storage of ram epididymal spermatozoa.

Keywords

• milk
• tris
• sodium citrate
• caproic acid