Pre and postpartum feed supplementation in ewes; effect on puberty and reproductive activity of the ewelambs

Fifty mature pregnant Romney Marsh awes were used to investigate the influe nce of feed supplementation during the pre and post lambing period and subs equent 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 th e other group (n=25) was not-supplemented (OC). Ewe liveweight, body condit ion score (BCS), lamb birthweight and ewe-lamb reproductive performance at first reproductive season war evaluated trough progesterona measurement in blood serum, using RIA technique. Lamb birthweight were not statistically d ifferent (P >0.05) from the OC and OS groups. There was. however, significa nt improvement (p <0,05) of weights (OC=31.2 kg and OS=35,8 kg). age of pub erty of ewe-lambs (2 10 days and 178 days), and lambing rate for ewe lamb ( 33% v/s 58%) for OC and OS groups. In conclusion the eu;e-lambs from supple mented dams improved their growing rate and reproductive indexes during the first breeding season.