EFFECT OF UNRESTRICTED ENERGY ALLOWANCE DURING LATE GESTATION ON TWIN-BEARING EWES' PERFORMANCE, LAMBS VIABILITY AND THEIR GROWTH

The present study was conducted to evaluate the effects of feeding rations with either restricted energy (E1) up to 100% or unrestricted energy (E2) up to 120% on Rahmani ewes' performance and their offspring lambs viability, behavior and growth. Twenty twin-bearing. ewes were allocated to E1 and E2 dietary treatments (n=10 in each). Both E1 (included concentrate feed mixture (CFM) and roughage as berseem hay (BH) and rice straw (RS) and E2 received the same ration with the addition of daily 1% of PF Megalac® from dry matter intake / head). Both E1 and E2 groups were fed from day100 age of gestation up to weaning of lambs. All ewes in E1 and E2 treatments received adequate level of protein form day 100
up to weaning. As expected, increasing energy source has improved (P <0.05) the ewe body weight (BW) and body condition score (BCS) prepartum. The E1 ewes lost more BCS in lactation compared with the E2 ewes. There was higher (P<0.05) effect of E2 nutrition on behavioral scores of the lambs as birth assistance, lamb vigour and suckling assistance and lamb birth weight than E1 ewes. Moreover, there was a considerable reduction of number of E1 lambs from birth to weaning, due to stillbirths, deaths, and life-support during this period. Early live weight gain and weaning weights of lambs increased nominally with increasing prepartum energy allowance of their respective ewes. However, only lambs in complete twin litters had significant increase in live weight gain until weaning (P <0.05). The quantities of NEFA concentration in blood of E1 were higher (P<0.05) than E2 ewes. It could be concluded that it is possible for twin-bearing ewes to meet the increased nutritional demand via intake, and even gain BCS, in late gestation when feeding energy intake is high. The
highest energy intake in ewes during late gestation increased energy mobilization during lactation that seemed to benefit lambs in twin litters with a growth advance until weaning. Also, unrestricted energy ration can improve the income of farmers at time of sailing lambs after weaning with better growth rate.