Grass seeds in sheep - a piercing issue
Grass seeds cost sheep producers and the industry many millions of dollars annually through production losses and downgrading of products.
With the current season favouring high seed production, sheep producers are reminded to be aware of the risks and attentive to their management, ensuring sheep and lambs remain seed-free.
Meat processors have sent clear messages that contamination costs, with downgrades in prices of up to $1.50 per kilogram of carcase weight. Infested carcasses need to be trimmed heavily, reducing returns to producers and risking access to high value export markets.
Grass seeds also have major implications for on-farm production and animal welfare.
Seeds become attached to the fleece and quickly become embedded in the skin and muscle and can also cause damage to the eyes, mouth, ears and feet.
Infested animals generally have lower bodyweight and growth rates due to bacterial infections, reduced feed and water intake, blindness, lameness and often, severe pain.
Grass seeds also have a major impact on the vegetable matter content of fleeces, resulting in discounts and higher processing costs.
Having a long-term management program in place is best practice. Identifying practical solutions to keep lambs and sale sheep free of seed is extremely important.
Short-term strategies include spray topping and slashing, but this will only reduce not eradicate problem species.
Identifying the problem grasses, and when they set seed is the critical step.
Barley grass, Spear grass, and Chilean needle grass are particular species of note in the Central West area.
Problem paddocks should be grazed before the grasses set seed, with the objective being to have enough clean paddocks set aside for when they are needed.
An integrated approach is the most effective, involving both pasture and animal management practices.
Encouraging the establishment of other competitive and safe grass species, strategic short-term heavy stocking rates to reduce potential infestations, shearing sheep before grass seeds mature, and the use of cattle to help clear access to shorter feed for sheep, are all options which, together with strategic paddock preparation can help reduce risk.
Remember that the ultimate goal is to eliminate the primary problem, the seeds, with a management program that has a year-round focus.
Meat & Livestock Australia have produced a publication ‘Winning against seeds’ which provides producers with a wide variety of valuable information about managing seed contamination in sheep. The publication is available for free download via their website.
If you would like any further information about the effects of grass seeds on your flock, speak to your Local Land Services Livestock Officer or District Veterinarian.