Grass seed control important

Key points:

  • The issue of grass seeds has an impact throughout the supply chain
  • Wean lambs to grass seed free paddocks
  • An integrated approach to management is most effective

Grass seeds cost producers and the sheep industry thoughout the supply chain many millions of dollars annually, through poor production and downgraded product. This year, producers are indicating it is one of the best seasons feed-wise in South Australia for many years but this also means that producers need to be very vigilant in their management to ensure lambs remain seed-free.

The cost of grass seeds impacts throughout the supply chain. It not only impacts on losses at the abattoir but also losses in production. On farm seed infestation from grasses like brome grass, barley grass, spear grass, silver grass and geranium can result in poor animal growth rates, susceptibility to infections, tetanus, flystrike and damage to eyes, ears, feet and the mouth.

Grass seeds first infest the animal’s fleece and within days the seeds are imbedded in the skin and carcass of the animal. Substantial wastage can occur as carcases need to be trimmed and product downgraded, resulting in lower prices. Producers can also experience losses in carcass weights due to serve trimming. Skins that have been infected with grass seeds are also financially penalised. The value of a skin that is infested with grass seeds could be devalued as much as 50%.

Management options should be part of a long term program, however in a year like this, short term strategies may need to be implemented. The objective is to have enough clean paddocks for your livestock (especially lambs), to get them through post grass seed set until clean feed such as stubbles becomes available. Paddocks prepared for lambs need to be monitored regularly as it only takes a few plants along the fence line or trees for lambs to become infested with seeds.

It is too late for winter cleaning which leaves spray topping, spray grazing and slashing but timing is critical with these operations. Another management option may be the confinement feeding of lambs.

Processors do offer a trial seed kill service where a portion of a mob randomly selected can be processed. Monitored closely through the abattoirs, the seed contamination is assessed and feedback given to the producer. This will help assess the true dollar impact to your business of grass seeds.

The most effective control against grass seeds is an integrated approach which involves the management of grazing, agronomy and stock in conjunction with careful selection of target markets and turn-off times. Management should also focus on reducing the number of problem grasses, including the seed bank.

MLA publications "Winning against seeds" bulletin and fact sheet, outlines both the impact of seeds and addresses short and long term strategies that need consideration by lamb producers. These publications can be downloaded from

Go Back To Search