Effect of addition of melatonin to the intravaginal sponges on oxidative status and reproductive performance in Iraqi awassi ewes

Abstract

Abstract This study was achieved to know the effect of addition of melatonin to intravaginal sponges impregnated with progesterone on oxidative status and reproductive performance in Iraqi awassi ewes. Twelve non-pregnant ewes were selected with an age ranged between 2-4 years, and weight with a mean of 42.8 ± 5.3 kg. The animals were divided in to two equal groups. Each group contained 6 animals. The first groups were treated with sponges free from melatonin; the second group treated with sponges contained two grain of melatonin in a dose of 6mg (3mg/grain) by putting them inside the sponges through small opening. All ewes were injected with eCG (250 i.u/ i.m) after the removal of sponges on day 12. Two Rams were introduced on the next day after removal of sponges. Blood samples were collected on day 0, 3, 7 and 12 from insertion of vaginal sponges for measurements the total leukocytes count and the level of malondialdehyde in plasma during the days of treatments with vaginal sponges. The result of study showed a significant increase in the level of malondialdehyde during the days of treatments for both groups. The results also showed that there was no significant difference between two treated groups in percentages of appearance of estrus, the period from removal of sponges to the appearance of estrus, pregnancy rate and fertility rate. It was concluded from this study that the use of vaginal sponges for estrus synchronization in ewes leads to increase the level of oxidative stress and the addition of melatonin with a dose 6mg to the sponges have no effect to decrease the level of oxidative stress that leads to vaginal inflammation concerned the intravaginal sponges. Key words: Melatonin, Oxidative stress, Reproductive performance, vaginal sponge, Ewes