Effect of Melatonin Supplementation to Freezing Extender on Post-Thaw Sperm Kinetics, Antioxidant Capacity and Fertility Traits in Buck Rabbits

Abstract

This study was carried out to monitor the fertilizing ability of rabbit semen frozen in the presence of melatonin as antioxidant. Semen from 10 mature Egyptian Baladi red bucks was pooled, extended with Tris-glucose-citric extender (1:1 v/v) supplemented by three concentrations of melatonin (10 -9 , 10 -6 and 10 -3 M) in addition to control, and finally cryopreserved at -196°C. After thawing, sperm kinetics, antioxidant capacity and fertility traits were evaluated. The results showed that total and progressive motility percentages were higher significantly in samples cryopreserved by melatonin (10 -6 M) as compared to control group. Curvilinear and average path sperm velocities were significantly higher in melatonin groups of 10 -9 and 10 -6 M than in the control group. Supplementation of melatonin at 10 -9 M and 10 -6 M groups decreased (P < 0.05) malondialdehyde activity when compared to the control one. In contrast, the total antioxidant capacity and catalase activity were significantly (P < 0.05) elevated at concentration of 10 -6 M melatonin as compared to the control group. In addition, transcript abundance of NFE2L2 and SOD1 genes increased in groups supplemented with melatonin compared to the control group. The fertility trial indicated that pregnancy rate, and the total and live born increased significantly (P < 0.05) in rabbit does inseminated with semen of 10 -6 M melatonin group in compared to the control samples. Conclusively, these results concluded that using melatonin with 10 -6 M level in rabbit freezing extenders could be recommended to improve semen quality and fertilizing ability of buck sperm post-thawing.

Shielding effect of melatonin improves seminal quality and oxidative stress indices during chilled storage of ram semen

“…Compared to control group, TAC activity owned signi cant improvement whereas MDA was signi cantly lower in MLT supplemented group indicating positive effect of MLT on seminal quality during incubation period. These results were in agreement with previous reports in ram (Dai et al, 2018;Mohamadi et al, 2018); buck (Dessouki and Sakr, 2019) and bull (Ashra et al, 2013;El-Raey et al, 2015). Moreover, the increased concentration of TAC along with decreased levels of MDA in MLT supplemented group con rm and explain the antioxidant potential of MLT in protecting seminal quality throughout the chilled storage.…”

Age-Dependent Computer-Assisted Sperm Analysis of Buck Semen Supplemented with Different Antioxidants

“…Collected two consecutive ejaculates twice a week from each rabbit. Ejaculates are immediately transported to the lab after collection and maintained there in a water bath at 38.5 0 C until the relevant examination [20] .…”

“…The ratios of spermatozoa with linearity and straightness were manually recalculated. Only ejaculates with progressive motility of at least 70% were pooled [20] .…”

“…After that, to prevent cold shock, straws fixed horizontally on a metal rack were placed in a freezing floating boat and exposed to liquid nitrogen (N2) vapors. After 15 minutes, the loaded straws were instantly lowered into the liquid nitrogen and held until their respective evolution [20] .…”

“…Also, 0.5 mL of antibiotic from Bio west-penicillinstreptomycin checker-dispersed in 100 mL of distilled water. Adding three moles of dimethyl sulfoxide (Riedel de Haen -27109) and 0.1 moles of sucrose (BioBAstigimgC12H2201) to 100 mL of extender will cause it to freeze (diluent) [20] . Antioxidant preparation: The molecular weight of melatonin is 232.28 g/L (Sigma, M5250-1G).…”