Viability of caprine spermatozoa in sodium citrate-egg yolk extender at room temperature

Résumé

This work was aimed at evaluating the ability of sodium citrate-egg yolk extender to sustain the viability of spermatozoa in semen stored at room temperature over a period of time as well as determining the best dilution ratio for on-farm artificial insemination. Seven matured West African dwarf bucks were used for this study; semen was collected once weekly with electro ejaculator, maintained at 37 C in the water bath during extension and was evaluated immediately after extension at room temperature until motility dropped below 20%. The semen collected were pooled and divided into 5 portions. Each portion was extended with sodium citrate-egg yolk extender at 1:0 (without extender, control) as T1, (1:1) T2, (1:2) T3, (1:3) T4 and the 5th portion was extended with normal saline at 1:1 (T5) which served as the negative control. Sperm motility, spermatozoa concentration, livability, acrosome integrity and morphological abnormalities were assessed and data obtained were subjected to analysis of variance. Results showed that spermatozoa motility in treatments 1, 2, and 5 differed significantly (P<0.05) from treatments 3 and 4 at 0 hour assessment. At two hours, sperm motility was 0% in T3 and T4, while sperm motility in T2 (81.67%) was not significantly different from T5 (76.67%) and T1 (86.67%). Percentage of normal sperm cells was significantly (P<0.05) lower in T4 than treatments 1, 2, 3 and 5. At four hours of assessment, sperm motility in T1 and T5 were significantly (P<0.05) higher than T2, while livability was significantly higher in T2 than T4 but was similar to T1, T3 and T5. There was also significant (P<0.05) reduction in livability as the extension ratio increases among treatments. Sodium citrate-egg yolk extender was able to preserve the viability of spermatozoa up to two hours at 1:1 extension ratio at room temperature. This study suggests that the dilution ratio of 1:1 is recommended for on-farm artificial insemination in goats when sodiumcitrate-egg yolk extender is employed at room temperature.