Follicle growth, ovulation rate, body weight change, and antioxidant and metabolic status in three fat-tailed sheep breeds fed a half-maintenance diet

Abstract

This study aimed to determine the impact of feeding a half-maintenance diet on ovulation rate, metabolic status, and antioxidant status of three native breeds of fat-tailed sheep under Egyptian conditions. Estrus was synchronized with two doses of cloprostenol 11 days apart. The number of preovulatory follicles and corpora lutea were evaluated by transrectal ultrasound. Total antioxidant capacity, superoxide dismutase (SOD), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), total cholesterol, insulin, and glucose were measured in serum. Breeds and treatments were used as fixed factors using univariate general linear model; within-treatment (control, restricted), simple one-way analysis of variance and within-breed, independent samples t-test were used. The results revealed significant effect of treatment (P=0.001) and breed (P<0.046) on ovulation rate. Glucose, total antioxidant capacity, and total cholesterol increased, but insulin decreased, due to the dietary restriction. LDH and SOD levels increased due to the dietary restriction. Restricted ewes had insignificantly decreased body weight, but the amount and percent of decrease compared to initial body weight was significantly high in restricted Rahmani ewes and low in Barki ewes. In conclusion, fat tail helped ewes of different breeds could withstand adverse nutritional conditions for 1 month with minimal effects on body weight, ovulation rate, and metabolic and antioxidant status.