Understanding mastitis in ewes

Results:

This project demonstrated that subclinical mastitis is very common in suckling ewes and that the majority of udder infections are manifest as subclinical mastitis rather than clinical disease.

Subclinical mastitis does have an impact on production thus farmers should be aware of the importance of maintaining udder health in order to maximise production. We demonstrated that older ewes, those in poor body condition and those with poor udder conformation were at greater risk high SCC.

Meanwhile subclinical mastitis was associated with suboptimal weight gain in lambs over the first 8 weeks of life. Teat lesions (which may be an indicator of suboptimal nutrition), poor udder conformation and old ewes were also associated with lower than expected lamb weights over the first 8 weeks of age.

Planned activity:

Some of the results have already been used within BRP material, e.g. udder-shaped leaflet. The results will also be fed into the other two studentships (CASE funded) on mastitis at Warwick University.

The Problem:

Mastitis in ewes is one of the greatest causes for concern among pedigree and commercial sheep farmers in GB. It is estimated that approximately 5% of ewes get acute mastitis with up to 50% of these ewes dying and 90% losing the affected quarter. A further 20-30% of ewes get sub-clinical mastitis during lactation.

Project Aims:

1. To investigate the prevention and treatment of mastitis in ewes suckling lambs
2. To generate a list of guidelines to help sheep producers tackle the issue

Approach:

Three longitudinal studies were used:

• to characterise the patterns of somatic cell count (SCC) in ewes over the first 10 weeks of lactation
• to identify factors associated with intramammary infection (IMI) and the impact of IMI on lamb growth