Abstract
In the present work, two experiments were conducted to investigate the efficiency of supplementing buck sperm medium with Moringa oleifera leaves extract on liquid-chilled storage and cryopreservation capacities of spermatozoa. Twenty ejaculates were collected by an artificial vagina from 5 Damascus bucks, 4 ejaculates each, during September-October. The pooled specimens of each collection session were diluted (1:10) with Tris-citric egg yolk extender, and were split into 6 equal aliquots. The first aliquot served as control (moringa-free), whereas the other five aliquots were supplemented with 0.05, 0.1, 0.2, 0.3 or 0.4 mL/ml (v/v) moringa leaves extract, respectively. The samples were then stored and maintained at 4 oC for the subsequent 48 h during which sperm traits were assessed alongside malondialdehyde (MDA) production and glutathione peroxidase (GPX) activity. The optimum concentration of moringa leaves extract that showed potential for maintaining sperm traits throughout the chilled storage period was further investigated for preserving the lifespan of spermatozoa after exposure to the cryopreservation stress against control. The results showed that moringa leaves extract supplementation reduced (P<0.05) the oxidative stress on spermatozoa and recorded a positive correlation (P<0.01) with sperm motility (%), viability (%), normal sperm (%), acrosome integrity and GPX activity (r= 0.36, 0.42, 0.61, 0.79 and 0.35, respectively) while recording a negative correlation (P<0.01) with production of MDA (r= - 0.56). Furthermore, supplementing buck sperm medium with 0.4 mL/ml moringa leaves extract efficiently improved (P<0.05) all sperm characteristics and decreased (P<0.05) DNA fragmentation index (DFI) post thawing compared to those of control. These results imply the powerful potential of moringa leaves extract as an exogenous antioxidant supplement in buck sperm medium particularly when spermatozoa are used for AI and IVFM applications.

Key words: Moringa, buck semen, chilled storage, oxidative stress, cryopreservation