The Effect of Melatonin Administration on Colostrum IgG Levels and Oxidative Stress in Advanced Pregnant Awassi Sheep

The aim of the present study was to investigate the effects on oxidative stress markers and colostrum quality levels of subcutaneous implantation of melatonin in the 4th month of pregnancy in Awassi sheep by considering the sex of offspring born. The animals consisted of 60 healthy Awassi female sheep. Progesterone-based oestrus synchronization was applied to the sheep during the breeding season and pregnancy examinations were performed by the transabdominal route. The pregnant sheep were divided into 2 groups: the melatonin (n=30) and control (n=30) groups. In the 4th month of pregnancy, melatonin was implanted subcutaneously behing the ear of each animal in the melatonin group, and 1 ml of saline was applied subcutaneously to the control group. Colostrum samples from all the sheep and blood samples from both sheep and lambs were taken within the first hour after birth, before the lambs were suckled. Colostrum IgG levels were seen to be higher in the melatonin group compared to the control group (p<0.001); higher in the group with no female offspring compared to the group with female offspring (p<0.001) and higher in twins compared to singletons (p<0.001). The colostrum IgG levels were higher in ewes with singleton birth in both the melatonin and control groups compared to those with no female offspring at birth (p<0.001). Serum total antioxidant capacity (TAC) levels in sheep was higher in the melatonin group than in the control group (p<0.001). Serum total oxidant capacity (TOC) and oxidative stress index (OSI) levels were higher in the control group than in the melatonin group (p<0.001). The serum TAC level in lambs was higher in the melatonin group than in the control group (p<0.001), and was higher in singleton lambs than in twins (p<0.001). The serum TOC and OSI levels were higher in the control group than in the melatonin group (p<0.001) and higher in singleton lambs than in twins (p<0.001). In conclusion, the use of prepartum melatonin may be considered in sheep breeding enterprises to improve the antioxidant defence system of the body and improve the quality of colostrum for newborn lambs to be able to gain sufficient immunity.