Performance, Health Status, and Colostrum Yield of Twin-Bearing Afshari Ewes as Well as Growth and Survival of Their Offspring are not Affected by Increasing Dietary Metabolizable Protein in Late Pregnancy

The aim of this study was to investigate the effects of two dietary metabolizable protein (MP) concentrations on the performance and health status of Afshari ewes and survival and growth of their lambs during late pregnancy. For 6 weeks prior to lambing, 32 Afshari ewes were randomly assigned to two dietary treatments, containing low (LMP) or high (HMP) MP concentrations. The ewes in LMP (n=16) and in the HMP (n=16) were individually fed with isoenergetic (2.39 Mcal ME/kg DM) diets that contained 99.4 and 116.5 g crude protein (CP) and 70.5 g and 84.6 g MP/kg dry matter (DM) respectively. The concentration of MP in the late pregnancy diet did not affect changes in body weight and body condition score of ewes as well as blood glucose, total protein, non-esterified free fatty acids (NEFA), b-hydroxy butyrate (bHBA), insulin concentrations, insulin sensitivity and total number of white blood cells (WBC), red blood cells (RBC) and other blood cells. Similarly, the amounts and composition of colostrum obtained during the first 24 h after lambing were not affected by MP level. It was concluded that increasing the MP content of the diet for 6 weeks prior to lambing above the standard requirements resulted in no benefit in terms of the productive performance and health indices of twin-bearing ewes and their offspring.