The influence of ewe weight at mating on lamb performance and reproduction of the ewe

Abstract

The condition score and body weight of ewes at mating have well-established effects on reproductive performance and future performance of the progeny in commercial flocks. The aim of this study is to investigate one of these effects, that of ewe weight at mating on ewe reproductive performance and lamb performance in LAMBPLAN flocks (Terminal and Maternal sire breeds). Ewe weight at mating had a significant (P<0.001) effect on body weight of the progeny and reproductive traits of the ewe. The effects on lamb body weight ranged from 0.03 kg at birth to 0.18 kg at hogget age per kg of extra ewe weight at mating. The effect of reproductive performance of the ewe was an additional 0.002 lambs born and lambs weaned per additional kilogram of ewe weight at mating. The genetic parameters estimated showed no significant change in the heritabilities of any of the traits investigated with the inclusion of the ewe weight at mating effect.