Effect of fat supplementation on serum concentrations of progesterone, insulin, growth hormone and some lipid metabolites in Pelibuey ewes

Abstract

In this study, multiparous Pelibuey ewes were used to determine the influence of calcium soap of fatty acids (CSFA) and bovine fat in the diet on serum concentrations of insulin, somatotropin, progesterone and lipid metabolites (total cholesterol, high and low density lipoproteins and triglycerides). Ewes (n = 6 per group) were assigned randomly to a diet that contained 1.5% CSFA (CS) or 1.2% bovine fat (S), or to a control diet (T) with no additional fat. The diets were provided during 75 days. Weight gain among treatments was similar (P > 0.05). The concentrations of lipid metabolites and progesterone were not affected by the diet (P > 0.05). Insulin concentration was higher (P < 0.01) in ewes that consumed additional fat and higher (P < 0.001) in S than in T and CS. The somatotropin concentration was lower (P < 0.05) in ewes of groups CS and S than in T. The number and size of pulses of somatotropin among treatments were similar (P > 0.05). In conclusion, bovine fat and calcium soap of fatty acids incorporated in the diet of Pelibuey ewes, in the indicated proportions, did not affect weight gain, progesterone concentration or lipid metabolites, but the bovine fat increased the serum concentration of insulin, reducing that of somatotropin.