Abstract

Fifty mature pregnant Romney Marsh ewes were used to investigate the influence of feed supplementation during the pre and post lambing period and subsequent ewe-lambs growth rates and pubertal events and reproductive activity during their first breeding season. Ewes were maintained in a pasture and divided into two groups: one group (n=25) was supplemented (OS) for 50 days after and 50 days before lambing with 2 kg of grassland silage/day, and the other group (n=25) was not-supplemented (OC). Ewe liveweight, body condition score (BCS), lamb birthweight and ewe-lamb reproductive performance at first reproductive season was evaluated trough progesterona measurement in blood serum, using RIA technique. Lamb birthweight were not statistically different (P>0,05) from the OC and OS groups. There was, however, significant improvement (p<0,05) of weights (OC=31,2 kg and OS=35,8 kg), age of puberty of ewe-lambs (210 days and 178 days), and lambing rate for ewe lamb (33% v/s 58%) for OC and OS groups. In conclusion the ewe-lambs from supplemented dams improved their growing rate and reproductive indexes during the first breeding season.