IMPROVEMENT OF SEMEN QUANTITY AND QUALITY IN OSTRICHES BY OXYTOCIN INJECTION BEFORE SEMEN COLLECTION

Abstract The effect of intravenous oxytocin injection before semen collection on semen quality was investigated in ostriches. Six clinically healthy ostriches, aged 3-5 years, previously trained for semen collection by manual stimulation were included in the experiment. These ostriches were routinely used for semen collection. Prior to oxytocin injection, they were subjected to 2 successive semen collections, 4 days apart. Then, they rested for another 4 days after the second semen collection. On the day of the third semen collection, the birds were intravenously injected with 5 IU of oxytocin via phallic vein. Semen collection was attempted 5 min after the injection. Four days after the third semen collection, ejaculates were again obtained from the birds. Seminal characteristics included in the evaluation were semen volume, percentage of motile sperm, sperm concentration, percentages of live, abnormal, and hyo-osmotic swollen spermatozoa. Semen volume was increased from 0.27 ± 0.08 and 0.23 ± 0.06 ml (8 and 4 day before injection, respectively) to 0.95 ± 0.17 ml (p < 0.05) on the day of oxytocin injection and returned to 0.26 ± 0.08 ml 4 days later. Sperm motility was also increased from 18.13 ± 9.26 and 23.75 ± 9.76% (8 and 4 day before injection, respectively) to 57.5 ± 12.54 (p < 0.05) on the day of injection and returned to 23.75 ± 10.68% 4 days after injection. Sperm concentration expressed similar results, and higher concentration was obtained on the day of injection (753.13 ± 354.94 × 10 6 cells/ml) compared to 8 and 4 days before and 4 days after injection (62.25 ± 31.68, 143.06 ± 102.91 and 70.78 ± 32.33 × 10 6 cells/ml, respectively, p < 0.05). Oxytocin enhanced the percentages of live and membrane integrity in the same manner. The percentage of live spermatozoa was higher with oxytocin injection (73.50 ± 12.55%) than the others (ranged 21.63-44.25%, p < 0.05). The percentage of swollen sperm (hypo-osmotic swelling test) in the day of oxytocin injection (65.25 ± 13.10%) was higher than the others (ranged 15.13-31.31%, p < 0.05). No significant effect was found on percentage of abnormal sperm. We concluded that oxytocin injection before semen collection improved most seminal characteristics in ostriches. Whether or not the injection depleted sperm reserve may need further study