effects of vitamin d3 supplementation during mating or gestation on antioxidant status and reproductive parameters in gray shirazi ewes

Recent studies suggest that vitamin d3 may have preventive and therapeutic effects on autoimmune disease, cancer, and type 1 and 2 diabetes beyond the skeletal condition and calcium metabolism. to demonstrate the effects of a single 10,000 iu/kg vitamin d3 im injection during mating and pregnancy on reproductive and antioxidant factors, 21 gray shirazi ewes with a parity of 1 to 3, which were kept under industrial conditions, were used for this research. all ewes underwent estrus synchronization by placing a sponge containing flurogestone acetate for 13 days, followed by an injection of 400 units of pregnant mare serum gonadotropin hormone on the 13th day. then, ewes were divided into three groups: the first group served as control (without any supplementation), the second group, called pre-pregnancy, received vitamin d3 10 days before laparoscopic insemination, and the third group, which received the supplement in mid-pregnancy (at the 15th week of pregnancy). blood samples were collected from the ewes at four different stages: the first stage was 10 days after vitamin d3 injection (at the time of insemination), the second stage occurred about 15 weeks after insemination (about 10 days after vitamin d3 injection), the third stage was 2 weeks before lambing, and the fourth stage took place 2 weeks after lambing. the study's findings indicated that vitamin d3 supplementation has no significant effect on reproductive factors in gray shirazi ewes (p≥0.05). however, a significant decrease in blood cortisol levels was observed during both pre-pregnancy and mid-pregnancy. additionally, there was a significant increase in antioxidant factors, such as superoxide dismutase and glutathione peroxidase, during mid-pregnancy. this conclusion can be related to the racial differences in sheep, the supplement's dose, and the timing and frequency of injections.