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 (P0,05) 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.