Grass seed lesions
General description
- Grass seeds reported at the abattoir refer to seeds found in the carcass (in the muscle).
- At slaughter, seed contaminated carcases require trimming, which can result in significant reductions in carcase weight.
- Carcases may be downgraded and export markets put at risk.
Cause
- As lambs/sheep graze on or walk through seedy pastures/areas, seeds are collected in the wool and then enter the body within days.
- The greatest risk period for picking up seeds is October to January in most regions.
- A number of plant species cause grass seeds problems including:
- Barley grass
- Brome grass
- Chilean needle grass
- Erodium
- Silver grass
- Spear grass
- Wire grass
Different species are present in different areas. Find out which species may be in your area.
Clinical signs
- Reluctance to move, particularly young sheep and lambs.
- Eye, ear, face and mouth injuries which may result in blindness, lameness or loss of appetite.
- Flystrike secondary to grass seeds penetrating the skin.
- Rough, discoloured or cotted wool (from biting or rubbing).
Diagnosis
- Seeds will be seen visually when the fleece is opened along the neck, jowl, and belly wool.
- At slaughter, if the carcass is skinned, you will see the extent of seed penetration on the underside
Treatment
- No treatment available against grass seeds.
- Seed-infested sheep can be relocated to seed-safe pastures but can remain contaminated for over two years, although the level of contaminating seeds is reduced rapidly over the first six months.
Prevention
Seed management strategies:
- Grazing management (stocking density, feedlotting, grazing rotation)
- Livestock management (time of lambing, shearing)
- Agronomic management (pasture manipulation, sown fodder crops, fodder conservation)
- Target market and time of turn-off
Learn more
Complete Guide: Winning against seeds - Management tools for your sheep enterprise
Seed contamination of carcases and management strategies