January 15th, 2022Fast facts on the grazing value of summer weeds

An informative article ‘Grazing value of summer weeds’ has been published in Spring Sheep Notes
2021, looking into the nutritional value of sheep eating weeds during the summer season.

Agriculture Victoria Livestock Extension Officer Raquel Waller said some summer weeds can
cause animal health issues, while others have nutritional value for sheep which may be worth
considering before deciding to spray and remove them.
Ms Waller said green pick over summer can provide protein, which is a necessary component of
the sheep’s diet and is important for the digestion of the low-quality dry feed that may be on offer.
“In the absence of a summer pasture species like lucerne, summer weeds can be of value.
“However, it is important to know your weeds, since toxic weeds can affect the health of the flock,”
she said.
The article outlines the nutritional value of some weeds that are potentially useful over summer.
It is a preview of the work conducted by Jess Brogden and Lisa Miller at Southern Farming
Systems (SFS), and will be published in early 2022 as a Weed Fast Facts booklet on Meat &
Livestock Australia’s (MLA) web hub www.mla.com.au/weeds and LESS WEEDS, BETTER
PASTURE – Southern Farming Systems (sfs.org.au)
Ms Waller said the pros and cons of grazing, rather than spraying out summer weeds in a pasture
needs to be considered in terms of how it affects the preferred grasses and clover during the
growing season.
“There can be competition for resources of light or shade, water and nutrients, problematic seeds
for livestock, issues of toxicity and chances of success. For example, buried wireweed/ hogweed
seed can last for up to 60 years.’
“Generally, a good quality sown perennial pasture will contain 30 – 50 per cent sown grass and 20
– 40 per cent subterranean clover, with annual volunteer weeds making up the rest of the pasture.
“Pastures that dry off over summer, decline in energy and protein as the plants go to seed and die
off. “High-quality pastures may still retain sufficient quality to support non-lactating animals for the
duration of summer–autumn, but poorer quality pastures will not benefit animals.
Find the article and more science-based information from Agriculture Victoria, including a range of
tools, tables and calculators, online via the Feeding Livestock website.