Effect of Different Egg Yolk Levels in Tris Extender With and Without Aloe Vera and Onion Crude Extracts on Surti Buck Semen at Refrigerated Temperature

Abstract

This study aimed to develop a suitable Tris-citrate-fructose-egg yolk (Tris) based extender with Aloe vera or onion extract to preserve Surti buck semen at refrigerated temperature. Semen ejaculates (n=96) collected by artificial vagina from eight bucks were split-diluted in Tris extender with 0, 5, 10, 20% egg yolk concentrations. All these were then fractionated into three aliquiots each, one fracrtion kept without further additives (EY0, EY5, EY10, EY20), while fractions 2 and 3 were an addition with crude filtrates of Aloe vera gel @ 10 µL (EY0+A, EY5+A, EY10+A, EY20+A) or onion extract @ 10 µL (EY0+O, EY5+O, EY10+O, EY20+O) per 0.5 ml of the extended semen. These samples (4x3 = 12 aliquots, each 0.5 ml) were then preserved at refrigerated temperature and evaluated at 12 hourly interval up to 48 h of storage for various sperm quality tests. Sperm motility was significantly lower (p<0.01) in all the subgroups with 0% egg yolk (EY0, EY0+A, EY0+O) compared to 5 to 20% egg yolk at all intervals. The sperm motility at 48 h was significantly (p<0.01) lower in EY0 without and with Aloe vera and onion (11.49 ± 2.54, 10.12 ± 2.45 and 6.58 ± 2.30 %) than EY5 without and with Aloe vera and Onion extract (53.85 ± 1.41, 56.82 ± 1.20, 34.84 ± 2.25%), EY10 without and with Aloe vera and onion (55.83 ± 1.19, 57.76 ± 1.10, 35.37 ± 2.15%), EY20 without and with Aloe vera and onion extract (56.09 ± 1.32, 56.46 ± 1.26 and 41.06 ± 1.92%, respectively). The live sperm count was significantly lower (p<0.01) in semen extended with 0% egg yolk as compared to 5, 10 and 20% egg yolk at 0, 24 and 48 hours. The post-chilled abnormal sperm percentage increased non-significantly at 24 and 48 hours in all extender combinations, although the effect of additives was non significant. It is concluded that adding egg yolk alone 5–20% or with Aloe vera extract @ 10 µL in semen extender had a beneficial role in Surti buck semen preservation at refrigerated temperature.