The effect of breeding ewe lambs on subsequent two-year-old ewe performance

This study was undertaken to determine if breeding ewe lambs (hoggets) would influence subsequent two-year-old (two-tooth) ewe liveweight and reproductive performance and their lamb's performance to weaning. Two-tooth Romney ewes that had been bred and lambed as a hogget (n = 505) were compared with those of 196 ewes that were bred as a hogget but did not lamb and 235 ewes that were not presented for breeding as a hogget. Hogget lambing resulted in reduced (P<0.05) two-tooth liveweight and body condition score at breeding although still present this liveweight difference was reduced by two-tooth lamb weaning. Two-tooth ewes that had previously lambed as a hogget had greater (P<0.05) returns to service rates and lower (P<0.05) fecundity (multiple-bearing/two-tooth bred) than those that were bred for the first time. Two-tooth lamb liveweights were unaffected by hogget lambing. These results show that hogget lambing had a small negative effect on subsequent two-tooth reproductive performance. This was most likely caused by reduced liveweight at two-tooth breeding and indicates that farmers need to ensure management practices are in place to reduce the impact of hogget lambing on two-tooth liveweight. (C) 2007 Elsevier B.V. All rights reserved.