The Effect of Different Levels of Energy Intake Before the Peripartum Period on Performance and some Metabolic Parameters in Ghezel Newborn Lambs

The aim of this study was to determine the effect of different energy intake before the peri-partum period on performance and some metabolic parameters in Ghezel newborn lambs. In this study, 15 mature Ghezel ewes after ultrasonographic confirmation of singleton pregnancy were used from 30 days prior to 30 days after lambing. Dietary treatments included: The control group with a diet that supplies 100% energy requirement of the animal, ewes under diet 70% (30% lower than animal energy requirement), ewes under diet 130% (30% higher than animal energy requirement). The amount of colostrum production and composition, daily milk yield, milk composition per week, birth weight, daily weight gain, and milk consumption in lambs were measured. Some plasma parameters immediately after birth, 24 hours later from birth and weekly until one month in lambs have been determained. The data obtained from this study on production and composition of milk showed that the diet 130% can increase the milk production (P<0.05). Colostrum production was significantly increased in  group fed with 130% energy level (P<0.05). However, in the 70% group, colostrum and milk production significantly decreased and the fat percentage has been increased (P<0.05). There was a significant difference between treatments of 130٪ of energy intake and other treatments in lambs weight, daily weight gain, and milk consumption so that the highest weight of lambing was in 130% group. There were no significant differences between treatments in aspartate aminotransferase (AST), alanine aminotransferase (ALT) and triglyceride (P>0.05). There was a significant difference between the treatments in relation to the immune system of lambs (P<0.05). The highest levels of immunoglobulin G and the lowest levels of plasma cortisol were observed in 130% group. It could be concluded that the high energy level intake in pre-parturition period, has led to an increase on ewe performance for produce heavy lambs, more milk and colostrum production, increase daily weight gain and high level of immunoglobulin G in lambs.