Effects of exogenous oxytocin on the semen characteristics of the Indonesian wild cattle, banteng (Bos javanicus), collected by electroejaculation: Implications for semen collection techniques and genome resource banking

Abstract

Developing protocols that maximize the total sperm output during a semen collection from an endangered species is essential for strategic genome resource banking practices. Exogenous oxytocin has been administered to domestic bovid species prior to semen collection to increase the total sperm count from a single collection. The hypothesis tested in the present study was that the administration of exogenous oxytocin prior to semen collection by electroejaculation (EEJ) would significantly increase the total sperm count of the ejaculate obtained from banteng. Banteng were administered exogenous oxytocin (50 i.u.) intravenously ∼10 min prior to EEJ. Ejaculates from 13 banteng (n = 6 oxytocin treated, n = 8 untreated) were assessed for volume, pH, osmolarity, sperm concentration, total sperm count, percentage of motile sperm, status (scale of 0–5; 0 = no forward progression, 5 = rapid straight forward progression). In banteng ejaculates, significant (p < 0.05) differences were observed in volume, sperm concentration, and total sperm count between oxytocin treated (Mean± SEM; 17.5 ± 3.7 ml, 2,138 ± 883.9 × 106 sperm/ml, 32,070 ± 8,812 × 106 sperm), and untreated (9.1 ± 1.8 ml, 308.8 ± 69.3 × 106 sperm/ml, 2,702 ± 763.7 × 106 sperm) bulls. These findings indicate that administering oxytocin to banteng prior to semen collection significantly increases total sperm count, and if routinely used, would maximize the number of banteng spermatozoa available in a genome resource bank. Semen was observed on the prepuce prior to the start of the EEJ procedure in three of the oxytocin-treated banteng, indicating oxytocin may be a useful agent to administer prior to other semen collection techniques such as urethral catheterization.