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Unlocking the keys to ewe survival

The results from this project can be used to inform management recommendations for improved ewe survival.

Project start date: 02 December 2018
Project end date: 10 November 2021
Publication date: 12 May 2022
Project status: Completed
Livestock species: Sheep, Lamb
Relevant regions: Southern Australia, Northern Australia, National, NSW, Western Australia, Victoria, South Australia, Queensland, Northern Territory, Tasmania, Eastern Australia
Download Report (3.3 MB)

Summary

This project sought to quantify the rates and causes of maternal ewe mortality. Mean cumulative ewe mortality over the lambing period was 2.0% in 2020 and 2.5% in 2019. The most common causes of mortality across both years were septicaemia, primary dystocia and trauma.

Objectives

The core research objective for this project was:

What are the major causes of ewe mortality in the lead up to and at the time of lambing for commercial non‐Merino flocks across a range of climatic zones?

The three research questions underpinning this objective were:

  • Estimate the prevalence of periparturient mortality in well managed, commercial non-Merino ewe flocks in southern Australia (from the time ewes are placed in their lambing paddocks until lamb marking).
  • Identify the causes of periparturient ewe mortality in commercial non-merino ewe flocks in southern Australia.
  • Identify the factors contributing to ewe mortality and the major causes of periparturient ewe mortality in commercial non-merino ewe flocks in southern Australia.

Key findings

The mean cumulative mortality over the lambing period was 2.0% in 2020 and 2.5% in 2019 with no significant difference between years.
• The primary causes of ewe death across both years were septicaemia, primary dystocia and trauma.
• The biggest single factor was dystocia, interlinked with other causes of death including septicaemia, trauma and hypocalcaemia.
• Factors that influenced ewe survival included parity (number of times pregnant), litter size, and age. The risk factors identified varied for each cause of death examined.

Benefits to industry

The results from this project can be used to inform management recommendations for improved ewe survival. These build on and reinforce the existing best practice guidelines promoted through programs such as Lifetime Ewe Management, with some new or additional guidelines now able to be added. Some of the findings from this project potentially offer significant gains for industry in improving ewe (and hence lamb) survival through either more targeted management or new management recommendations.

Resources developed by the project team for use during the project have been adapted and made available to industry. Scientific papers, producer case studies, presentations by the project team to industry and a project infographic are all mechanisms that have and will be used to share project findings.

MLA action

A webinar on the project outcomes can be viewed on the Sheep Reproduction Strategic Partnership webpage

Future research

Formally incorporate findings from this research into existing sheep reproduction extension packages, to enable these products to have greater impact on ewe and lamb survival.
• Refine recommendations specific to older (>5 years) ewes to maintain productivity and welfare over lambing for this age group (especially if retention of older ewes is used as a strategy to re-build flock numbers).
• Investigate the role of hypocalcaemia in periparturient ewe mortality and refine current recommendations on mineral supplementation.

• This project has highlighted current gaps in the understanding of ewe mortality, where improved knowledge could inform management recommendations to improve animal welfare and ewe productivity. These include:

  • Condition score targets for different ewe genotypes
  • The role of genetics in reducing dystocia in Australian flocks.
  • Management options that reduce impact of metritis for lambing ewes.
    Strategies for managing triplet bearing ewes to improve ewe (and lamb) survival.
  • Prevention and management of septicaemia, including association with dystocia.

Unlocking the keys to ewe survival resources

Maximising non-Merino ewe survival during lambing

This factsheet briefly summarises the key findings from the unlocking the keys to ewe survival project. It outlines lambing ewe mortality benchmarks, the key causes of death and primary risk factors, and the management practices that sheep producers can adopt to increase ewe survival during lambing. View the factsheet here.

 

Ewe lambing diary

This ewe lambing diary was used by host producers during the unlocking the keys to ewe survival project. Producers can use it to record ewe mortality information from when ewes are first placed in their lambing paddocks until lamb marking. Using this diary will help sheep producers to record ewe mortality data during the lambing period. This will help producers review the main causes of ewe deaths during the lambing period for their property and identify if there are any issues. Download the diary here.

 

Ewe survival post-mortem protocol

This post-mortem protocol was used by vets during the unlocking the keys to ewe survival project. It has been made available to industry, for sheep vets to use when helping their sheep producer clients get to the bottom of any animal health issues during lambing. View the protocol here.

 

For more information

Contact Project Manager: Joe Gebbels

E: reports@mla.com.au