Mitigating the impacts of weather on lamb survival in Southern New Zealand.pdf (1.08 MB)

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

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posted on 2023-07-11, 01:22 authored by David StevensDavid Stevens, Marie Casey

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


Sustainable Farming Fund (SFF)

Beef + Lamb New Zealand


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This work is licensed under a Creative Commons Attribution-Non Commercial-NoDerivatives 4.0 International License. Rights granted to the New Zealand Grassland Association through this agreement are non-exclusive. You are free to publish the work(s) elsewhere and no ownership is assumed by the NZGA when storing or curating an electronic version of the work(s). The author(s) will receive no monetary return from the Association for the use of material contained in the manuscript. If I am one of several co-authors, I hereby confirm that I am authorized by my co-authors to grant this Licence as their agent on their behalf. For the avoidance of doubt, this includes the rights to supply the article in electronic and online forms and systems.

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  • PRJ0140125


  • English

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  • No


New Zealand Grassland Association

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Journal of New Zealand Grasslands



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