Effect of Melatonin and Vitamin C as Antioxidants in Vitro Embryo Production in Local Iraqi Ewes

Abstract

Melatonin and vitamin C were tested on 155 reproductive tracts (310 ovaries) of local Iraqi sheep in aimed to investigate their effects on blastocyst generation. Oocytes were counted and cultured for 24 hours in a CO2 incubator with melatonin and vitamin C as antioxidants. Fresh semen was collected from two fertile rams by electroejaculator with the addition of heparin for capacitation at a rate of 10pg/ml. Matured oocytes grade good and fair were incubated in a CO2 incubator for 24 hours. Fertilised oocytes were cultivated in TCM-199 media with melatonin and vit c. Daily media replacement was 50%. The divided zygote developed every 24 hours until it formed a blastocyst after 168 hours and hatched after 216 hours after fertilisation. Addition of melatonin increased maturation rate to 60% (27/45) from 37.7% (20/53) with vitamin C and 22.2% (4/18) without antioxidants. Melatonin significantly differed (p<0.05) from vitamin C or control groups in the maturation group. The melatonin group had 59.2% (16/27) fertilisation, while the vitamin C 65% (13/20). There was no significant difference between groups. Maturing and fertilisation rates differed between the treated and control groups 22.2% (4/18) and 25% (1/4), respectively (p<0.5). With melatonin, blastocyst production was 62.5% (10/16). It was 53.8% (7/13) in vitamin C. Blastocysts were absent in the control group. Blastocyst production differed significantly (p<0.5) between the melatonin, vitamin C, and control groups. It was concluded from this study that the addition of an antioxidant (melatonin or vitamin C) could improve IVM, IVF, and IVEP in sheep.