Grass seeds

• 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. Some markets refuse to accept grass-seed-affected carcases.

• 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.
• Several 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.

• Reluctance to move, particularly young sheep and lambs.
• Eye, ear, face and mouth injuries which may result in blindness, lameness or loss of appetite. Mortalities up to 1% of lambs can occur following these injuries.
• Flystrike secondary to grass seeds penetrating the skin.
• Rough, discoloured or cotted wool (from biting or rubbing).

• Seeds are readily visible when the fleece is opened along the neck, jowl, and belly.
• At slaughter and after skinning you will evidence of seed penetration on the underside of the animal.

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, spray topping)
• Target market and time of turn-off

• There is no treatment for removing wide-scale grass seed infestations.
• Seed-infested sheep can be relocated to seed-safe pastures but can remain contaminated for over two years, although the level of seed contamination will reduce rapidly in the first six months after relocation.

MLA - Managing grass seeds

MLA - options for managing grass seeds

Seed contamination of carcases and management strategies

QLD - Avoiding impacts on sheep from grass seeds

DAFWA - Managing grass seeds in sheep

Grass seeds seasonality

Animal Health Australia - National sheep health monitoring project

Animal Health Australia - Virtual Reality tool (visualise the condition)