The Effect of Energy Deficiency on Plasma İnsulin and Cortisol Concentrations During Late Pregnancy in Chios Ewes

*Summary The aim of this study was to investigate the effect on plasma insulin and cortisol concentrations by feeding Chios ewes with a low energy ration in the late period of gestation. 38 Chios ewes were divided into three groups as pregnant normal energy (PNE), pregnant low energy (PLE) and non pregnant normal energy (N-PNE). Feeding with the treatment rations started on day 105 of the gestation and continued until lambing. Blood samples were obtained on days 120. 127. 134. 141. and 148. during gestation. Plasma insulin concentrations of ewes in the pregnant normal energy were significantly higher than those of the pregnant low energy on days 134 and 141. No significant difference was observed in plasma insulin concentration between pregnant normal energy ewes and non pregnant ewes. Plasma cortisol concentration of ewes in the pregnant low energy was lower on day 120 but higher on day 134 than those of ewes in the pregnant normal energy. As a conclusion an energy intake of greater than 10 MJ/kg ME should be assured for pregnant ewes in the late pregnancy, although energy level of 8.0 MJ/kg ME does not cause a serious energy deficiency.