Ewes that are performing in your flock are those that are consistently rearing lambs each year and weaning more kilograms of lamb each year. Retaining these ewes and removing those that aren’t performing will increase reproductive efficiency and selection pressure within the flock. What data are you collecting throughout the reproductive cycle to help you make informed decisions when selecting ewes to retain or cull from the breeding flock? 

Collecting ewes' reproductive performance data

Some of the key data that can be collected to assess the reproductive performance of ewes are:

• Pregnancy scan results (dry, single, twin or triplet)
• ‘Wet’ or ‘dry’ at lamb marking
• Number of lambs weaned and weight of lamb weaned (if you’re matching lambs to their dam)

Utilising EID and recording this data against each ewe every year provides a lot of power when making selection decisions. 

Identifying ‘wet’ vs ‘dry’ ewes at lamb marking

‘Wet’ or ‘dry’ udder assessment is a quick and easy way of determining whether a ewe has reared a lamb to marking: 

• ‘Wet’ ewes are those that are lactating and hence are rearing at least one lamb. These ewes will have birth stain on the breech, clean teats and a warm, full udder with white milk stripped from the teats. 
• Ewes that are ‘dry’ (a.k.a. ‘lambed and lost’) have stopped lactating because they are not rearing a lamb. They will also have birth stain on the breech, but their teats will be dirty and/or greasy. Their udders will be small, cool and floppy, and you will either be unable to strip any fluid from the teats or you will be able to strip a thick (or sometimes watery) fluid that is different to the colour of milk - often clear or it may be cloudy or have white flecks. 
• If you’ve not pregnancy scanned your ewes, then ewes that are ‘dry’ may also be ewes that have failed to conceive. These ewes won’t have any birth stain on the breech, but may have some udder development if they’ve lambed in a previous year/earlier lambing. 

Benefits of assessing udders at lamb marking

It’s best to assess udders as ‘wet’ or ‘dry’ at lamb marking because ewes may have naturally weaned their lambs by the time you conduct weaning, which means that you could incorrectly assess a ewe as ‘dry’. Assessing udders as wet or dry also presents a good opportunity to identify any ewes with unsound udders (e.g. missing or blown teats) or mastitis for culling. 

Research has shown that culling ewes that have consecutively failed to rear a lamb (twice lambed and lost) has a similar impact on lifting the reproductive performance of the flock as culling ewes that have consecutively been scanned dry at pregnancy scanning. The main benefit of culling these ewes is a decrease in the number of dry ewes in the flock. 

‘Wet’ or ‘dry’ assessment is a practice that’s performed when ewes are already in the yards for lamb marking/tailing, so why not take the opportunity to collect this valuable data if you’re not already doing so and push the reproductive performance of your flock to the neXt level.

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Join the conversation on The Hub

Take a moment to head over to the neXtgen Agri Hub to share your thoughts and questions about identifying your higher-performing ewes, along with any passengers in your system. What informs your decisions about which ewes to retain or cull from your flock?

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Further reading

You can head to this article for more information on what to look for when conducting udder assessments: Driving reproductive performance by removing the 'passengers'.