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Online Journal of Veterinary Research©


 Volume 22 (6):513-517, 2018.

Nocturnal and diurnal plasma melatonin in season and non-seasonal sheep during spring.


Saad Akram Hatif1, Laith Sofian Younis2


1College(s) of Veterinary Medicine, University of Baghdad, 2University of Tikrit –Iraq.




Hatif SA, Younis LS., Nocturnal and diurnal plasma melatonin in season and non-seasonal sheep during spring, Onl J Vet Res., 22 (6):513-517, 2018. Plasma melatonin was determined by ELISA in seasonal and non-seasonal Awassi ewes during Spring (Iraq). Nocturnal (29.058 ± 3.86pg/ml) and diurnal (23.061 ± 2.71pg/ml) plasma MLT concentrations were higher (P<0.05) in non-seasonal ewes compared with seasonal ones (20.00 ± 2.59 and 14.57 ± 2.36 pg/ml). We found plasma melatonin higher (P < 0.03) in non-seasonal ewes (26.059 ± 2.85 pg/mL) compared with seasonal ones (17.512 ± 2.06 pg/ml) during the Spring photoperiod. Results suggest that nocturnal MLT concentration is higher than diurnal concentrations in seasonal and non- seasonal local Awassi ewes at spring.


Key word : Melatonin, nocturnal, diurnal, seasonal, non-seasonal, Sheep.