Effects of calcium salts of fatty acids rich in palmitic and oleic fatty acids on reproduction and serum biochemistry in Barki ewes

- Supplementing the diet of Barki sheep with calcium soaps rich in Palmitic and Oleic fatty acids increased the female: male sex ratio of their lambs.
- Calcium salts of fatty acids rich in palmitic and oleic fatty acids increased serum estrogen and size of corpora lutea not progesterone secretion.

The effect of a flushing diet supplemented with calcium salts of fatty acids (CSFA) high in palmitic (37%) and oleic (33.6%) fatty acids on reproductive performance was studied using 30 Barki ewes with a mean weight of 40.0 ± 0.2 kg (mean ± SD). The control group (n = 15) received the basic diet of 1 kg/h/d concentrate plus Egyptian clover (Trifolium alexandrinum) hay ad lib and the CSFA group received the basic diet plus 50 g/h/d CFSA. The diets were offered for 60 days, prior to (30 d) and subsequent (30 d) to mating. Estrus was synchronized using a single injection of PGF2α prior to the introduction of rams. CSFA-fed ewes had non-significantly different twinning (20.0 vs. 7.1%), prolificacy (1.2 ± 0.1 vs. 1.0 ± 0.1) and female: male lamb sex ratio (72.2 vs. 50.0%) compared to controls; also, pregnancy, embryo survival and lambing rates were not affected by diet. Feeding CSFA resulted in a higher (P = 0.06) total number of follicles and number of large follicles; however, the number of small follicles, and diameters of small and large follicles were not significantly different. Serum concentrations of estrogen at estrus were higher (P = 0.06) 3 days after PGF2α administration in CSFA (52.3 ± 4.2 pg/ml) compared to for control (41.6 ± 3.8 pg/ml) ewes. There were no significant differences in total number of corpora lutea (CL) or serum concentrations of progesterone during the luteal phase. Diameters of nascent CL were increased (P < 0.05) by CSFA treatment (13.0 ± 0.7 mm) compared to control (11.2 ± 0.2 mm). Serum concentrations of lipid metabolites (TG, CHOL, HDL and LDL) were significantly (P < 0.01) elevated relative to controls in the CSFA treatment. Serum TP, G and liver enzymes (ALT and AST) were not significantly affected by treatment. It was concluded that including CSFA in a flushing diet for Barki ewes resulted in increased serum concentrations of lipid metabolites, and improved twinning and prolificacy rates, and female/male lamb sex ratios.