The aim of this project was to develop an udder scoring system associated with udder health, lamb survival and lamb growth rates and can accurately be used by farmers.
To do this, the following was investigated:
- recognise and describe the range of udder and teat defects found in commercially-farmed ewes
- factors associated with clinical and subclinical mastitis in ewes
- the impact of udder and teat defects and udder health on lamb survival and pre-weaning live weight gain.
Lambing percentages in New Zealand have increased over the past twenty years, putting increased emphasis on ewe udder health to enhance lamb survival and maximise pre-weaning growth rates.
Many farmers indicate that they examine the udders of their ewes and make culling decisions based on this. However, there is sparse information available, and therefore guidance, on what farmers should be examining and the impacts of various udder characteristics on lamb performance.
Without this knowledge, farmers may fail to cull ewes who will not rear lambs successfully or whose lambs will display poor growth rates. Conversely, they may incorrectly cull ‘sound’ ewes.
Key programme results
Udder scores can be used to determine culling decisions or identify ewes whose lambs had greater odds of failure to survive weaning.
Udder palpation, udder symmetry and clinical mastitis scores during lactation were associated with lamb growth rates.
Benefit to farmers
This project provided information and resources to more accurately assess ewe udder health and make sound culling decisions.
Lambs that are born to ewes with udder defects will have a reduced chance of survival and the lambs that do survive grow an average of 25g less per day than lambs whose dams had normal udders so for long term productivity, understanding udder defects is hugely important.
- Six to farmer and industry audiences.
Popular press articles
- B+LNZ website: “Udder issues limiting production”
- B+LNZ website: “Examining ewes’ udders to identify possible problems” video
- B+LNZ scene and herd podcast: “More and better lambs, just by checking ewes’ udders”
- B+LNZ factsheet: "Examining ewe udders"
- Webinar: “Why check ewe udders”
- The Journal: “Longevity and wastage in New Zealand commercial ewe flocks – a significant cost”
- Rural News: “Check ewes’ udders after weaning – study”
- Rural News: "Reducing ewe deaths could save $28m annually"
- New Zealand Society of Animal Production
- New Zealand Veterinary Journal: "Associations between lamb growth to weaning and dam udder and teat scores"
- New Zealand Veterinary Journal: "Investigating associations between lamb survival to weaning and dam udder teat scores"
- New Zealand Society of Animal Production: “Investigation into udder characteristics, mastitis and milk production in crossbred sheep”
Timeline and investment
This was a four-year project. B+LNZ investment was $345,000 over the duration of the project.
This work was led by Massey University and funded by B+LNZ, Massey University, the C. Alma Baker Trust and Lincoln University.
Lead Scientist: Anne Riddler.
B+LNZ point of contact: Suzanne Keeling.