The Effect of Melatonin Application on Sexual Behaviors, Reproductive Hormones and Performance in Dairy Sheep

Öztürk N., Yazgan N., Akbağ H. I., Tölü C.

4th International Congress on Agriculture, Environment and Health, Aydın, Turkey, 20 - 22 May 2021, vol.1, pp.161-162

  • Publication Type: Conference Paper / Summary Text
  • Volume: 1
  • City: Aydın
  • Country: Turkey
  • Page Numbers: pp.161-162
  • Çanakkale Onsekiz Mart University Affiliated: Yes


One of the most important characteristics of breeding in sheep is that it depends on the season.

The melatonin hormone is used to stimulate out-of-season estrus rather than stimulations of

heat. In this study, the effects of the melatonin implant applied before the breeding season on

sexual behavior, melatonin, estrogen and progesterone hormone levels and some reproductive

performances were determined in Tahirova sheep. In the study, 68 Tahirova dairy sheep

between the ages of 1-4 were used. In half of the sheep were administered an 18 mg dose /

sheep melatonin implant (Regülin®) on June 26. 15 days after implantation for 60 days grain

barley 530 g / ewe and 660 g / ram to be in the milking unit for ewes given to rams in group


On August 1, the sheep whose estrus was detected with the addition of a ram were taken to

individual chambers and mated by hand-mating method. While the frequency of sniffing,

touching of ram’s genitalia, turn of the ram, looking back to ram, and tail wagging were taken

during the hand-mating, sexual behaviors of the ram were also recorded. Besides, it was

determined whether there was an interaction at 1-minute intervals, the sexual interaction rate of

the sheep, the total frequency of sexual interaction, the time per sexual interaction and the total

sexual interaction time in the observations. In melatonin administration, blood was taken

regularly on initial (pre-implant), 21st day, 42nd day, 63rd day, 94th day, 129th day for hormone

analysis. The hormonal analyzes were performed using the Elisa method in blood serum

samples. Sexual behaviors were similar in the control and treatment groups (P>0.05). Sheep

sexual interaction rate increased significantly in the treatment group compared to the control

group (P=0.0045). In the study, the hormone levels of melatonin on the 21st and 42nd days and

estrogen and progesterone hormone levels on the 42nd day were higher than the

control group (P≤0.05). In the study, it was determined that the

melatonin implant significantly increased hormone levels on the 21st

and 42nd days, and shortened the periods of estrus, conception and lambing significantly. It

might be said that before the breeding season melatonin application, which does not show a

significant effect on lamb yields in Tahirova sheep, can be used to obtain lambs earlier.

Keywords: Tahirova, melatonin, estrogen, progesterone, estrus, sexual interaction rate.