Effect of supplementing a diet with monensin sodium and Saccharomyces Cerevisiae on reproductive performance of Ghezel ewes

Effect of supplementing a diet, in an attempt to enhance reproduction, with monensin sodium and Saccharomyces cerevisiae yeast on reproductive performance was investigated during the breeding season using 44 Ghezel ewes (body weight 56.97 ± 7.47 kg, age 2-5 years and body condition score (BCS) 2.5) which were allocated randomly in equal numbers to the four dietary treatments as follows: 1) Basal diet plus supplemental feed (450 g/ewe/d) plus monensin sodium (30 mg/ewe/d) (MS); 2) Basal diet plus supplemental feed (450 g/ewe/d) plus Saccharomyces cerevisiae yeast (4 × 109 CFU/ewe/d) (SC); 3) Basal diet plus supplemental feed (450 g/ewe/d) (FG); 4) Basal diet (only grazing on pasture, Control; G). Estrous synchronization of all ewes was done using controlled internal drug release (CIDR) and all ewes were mated with purebred Ghezel rams after CIDR removal. The results indicated that MS and SC treatments with 15 lambs had greater number of lambs than ewes of the other two treatment groups. Ewes in MS group with 50% twining rate had the greatest value followed by the FG, SC and G treatment groups (P < 0.05). The lambs from ewes in MS and SC groups were heavier in weight than those in FG and G treatments (P < 0.01). Blood sample analysis provided evidence that ewes in MS and SC groups had greater concentrations of 17β-estradiol (E2), progesterone (P4), blood urea nitrogen (P < 0.05), insulin, glucose, cholesterol and total protein (P < 0.01) than ewes of the other groups. These results indicated that using a diet for enhancing reproduction, including monensin sodium and Saccharomyces cerevisiae yeast in the breeding season could have beneficial effects on reproductive performance of Ghezel ewes.