Grazing summer weeds

Why spray when you can graze? Research has found 100 to 500kg of dry weed matter per hectare is enough to keep the liveweight of a dry ewe up, provided the weeds were reasonably high (5cm) and easy for the sheep to forage. Photo by Donna and James Winter-Irving

The nutritional value of summer weeds has been documented by a pair of Australian researchers.

The pair, Jess Brogden and Lisa Miller from Southern Farming Systems, looked at how well weeds in the January to March period could support dry ewes.

According to their ongoing research, wild radish/mustard, fat hen and green/spraytopped bent grass had consistently high crude protein percentages, hovering between 13 and 40 per cent.

Agriculture Victoria livestock extension officer Raquel Waller said while some weeds could cause animal health issues, others had nutritional value for sheep which may be worth considering before spraying.

Ms Waller said green pick over summer could provide protein — something vital for sheep and important in the digestion of low-quality dry feed.

“In the absence of summer pasture species like lucerne, summer weeds can be of value,” Ms Waller said.

“However, it is important to know your weeds.”

The recent article ‘Grazing value of summer weeds’ published in Spring Sheep Notes 2021 outlines what weeds work best as summer feed.

This article is a preview of work conducted by Brogden and Miller.

A full version will be released later in the year on the Meat and Livestock Australia and Southern Farming Systems websites.