Mitigating the impacts of weather on lamb survival in Southern New Zealand

Increased fecundity and improved feed management have doubled the number of lambs born in any threeday period spring since 1990. Four farmer catchment groups were engaged to investigate options that farmers may use reduce impacts weather at lambingtime. After workshops identified potential mitigations, a lamb survival model was developed using data from literature. This applied daily time steps over 20-year 1980-1999, with chosen mitigations added their impact. Direct intervention by improving pre-lambing ewe nutrition increased live 7-8% (P<0.05). Policy development strategies provide shelter 8 17% reductions wind speed 50 100% respectively These results consistent across all environments tested. Increasing net docking, though also resulted greater losses. Spreading risk spreading lambing did not alter long-term rate. Provision shelter, both before during lambing, ensuring adequate pre-laming most effective consistently