top of page

Grazing Winter Cereals

Agronomist Bec Whitby of Whitby Ag has a cameo appearance this month. Bec runs an elite, highly professional and independent agronomy business servicing Coolah, Cassilis and Merriwa. We love knowledge sharing and working in with Whitby Ag.

Trial data shows >25% improvement in ADG when supplementing Magnesium or Magnesium plus salt on winter cereals - read more below.

Supplements for cattle grazing winter cereal

Winter cereal crops in the area are now being stocked. These cereals (Wheat, Oat, Barley, Triticale) are extremely handy for filling the winter feed gap and provide a high quality fattening feed option.

Understanding animal requirements and balancing these with plant nutrients is important.

While winter cereals are slightly different in mineral compositions they do all have one thing in common, high potassium (K) concentration.

Potassium (K) at high levels accompanied with low salt (Na) interferes with rumen magnesium (Mg) absorption.

In many cases soil and plant magnesium (Mg) levels may be adequate, however animals still exhibit signs of magnesium (Mg) deficiency such as grass tetany due to high plant potassium (K) levels and low salt (Na).

Table 1: Mineral comparison of winter cereal crops to that of the daily requirements of the animal in percentage of dry matter (%DM).

* Daily requirements recommended by the NRC (2000) for beef cattle.

© Rebecca van Es University Western Sydney 2007

There are a few things you can do to increase the liveweight gains achieved in cattle over the total grazing period on winter cereals.

  1. Pre-grazing animal health - recent drench along with 5 in 1 vaccine to prevent pulpy kidney which can occur with a sudden change of diet.

  2. Introductory period - allow stock time to adjust to green feed.

  3. Put animals on full - ensure stock are not hungry and are introduced to the crop on a full gut.

  4. Provide roughage - straw or long hay (not lucerne) ad-lib is great as the chewing increases saliva production which can have a natural buffering effect in the rumen against acidosis, while also slowing the through pass of the cereal crop to allow more time for nutrients to be absorbed by the animal.

  5. Provide Magnesium and salt Supplementation - ad-lib access to a quality hi-magnesium and salt supplementation has been shown to significantly increase liveweight gains in cattle and sheep.

Trial data showed steers grazing cereals increased from 1.5kg/h/d LWG as control to 1.8-1.9kg/h/d LWG with Mg or Mg + Na supplement.

Table 2: The effect of supplementation on steer live-weight gain in the last four weeks of the trial

© Rebecca van Es University Western Sydney 2007

Dove, H., Kelman, W. M. (2015). Liveweight gains of young sheep grazing dual-purpose wheat with sodium and magnesium supplied as direct supplement, or with magnesium supplied as fertiliser. Animal Production Science, 55(10), 1217-1229.

McCormick, J. I., Pauler, J. W., Bell, L. W., Seymour, M., Ryan, M. P., McGrath, S. R (2021). Dual-purpose crops - the potential to increase cattle liveweight gains in winter across southern Australia. Animal Production Science. In Press

You can contact Whitby Ag on

Image via Dept Ag & Food WA


bottom of page