Recent strong winds in parts of the region have left barley heads on the ground, shattered canola and disappointed growers in its wake.
Grower reports suggest barley losses were between 1-2 t/ha. BCG trial plots at Birchip measured losses as high as 2.8 t/ha when comparing trial plots in the same location and with the same management.
Losses between crops will vary, but growers reported larger losses in varieties Compass and Planet, compared with others like Spartacus that have appeared to have retained heads better.
Can I measure the potential loss?
To estimate grain loss in cereals, estimate the number of grains between two crop rows along 50cm.
Grain loss (t/ha) = no. of heads x no. grains per head x avg. 100 grain weight (g) /10000
unit area (m2)
Eg. there are 25 heads x 18 grains per head x 4.2/10000 = 450 x 0.00042 = 1.26 t/ha
50cm x 30cm row spacing 0.15
Or a useful rule of thumb is: Every 25 grains per 0.1m2 quadrat (with 31.6cm sides) provides 100kg grain/ha.
Estimating feed value
The fallen barley heads present a grazing opportunity to recover grain value. Barley grain is highly digestible, with 12-13 MJ ME/kg dry matter and 11-12% protein. This is adequate nutrition for dry ewes or early to mid-pregnancy and lambs will grow well (a 2-4% protein top-up from supplementary feeding will maximise growth rates depending on genetics and age).
Barley grain also contains high levels of readily digested starches and low levels of fibre, so care must be taken when introducing sheep to prevent grain poisoning or acidosis. When more grain is eaten than can usually be digested, carbohydrate is released into the rumen. Bacteria rapidly ferments this to lactic acid which lowers the rumen pH resulting in acidosis, slowing of the gut, dehydration and often death.
How do I introduce sheep to grain safely?
To prevent grain overload, some useful guidelines are:
- Check pulpy kidney vaccinations are up to date and vaccinate before grain feeding if necessary.
- Train sheep onto the grain gradually. If there’s a lot of barley heads and grain left in the stubble, begin by trail feeding in their current paddock before introducing to the barley stubble.
- During the introduction phase, feed grain daily. Start with 50g per head on the first day, followed by increases of 50g every day until a full ration is reached.
- If possible, use oats and lupins first before transitioning to barley. To transition, increase the barley portion by 25% of the oat ration every five days over 16 days.
- Fibre stimulates saliva production, which contains the natural buffer bicarbonate. Provide fibre or a bicarbonate supplement if paddock feed is low while trail feeding. There will be adequate fibre once on the stubble.
- Alternatively, you may move lambs in and out of the barley stubble over 10 days of adjustment. To avoid gorging, introduce to the paddock late in the day with full bellies, and only leave on for a short time initially then gradually increase the time each day.
You may find you can get sheep onto rations quicker, other times it may be slower. Monitor your flock for signs of scouring, unhappiness, lethargy, disjointed gait or lameness, which will indicate the amount of grain is being increased too soon.
Is it worth it?
For a back of envelope example (Table 1), if we value the barley at $245/t and grazing loss at 20% (an estimate of trampling and burying, could vary between 15-40%), there will be about 1t/ha grain accessible for sheep production.
Table 1. Estimating grazing value ($/ha)
|Grain loss (t/ha)||Gross loss
Grain value ($/ha)
|DSE grazing days*||Gross margin
Prime lamb/Merino ewe enterprise Grazing value ($/ha)**
*DSE grazing days = (DM (kg/ha) – wastage) x feedtest ME (we used 12 MJ)/ 8 MJ (1 DSE requires 8 MJ /day) 2020 Prime lamb/Merino ewe GM/DSE = $70, pers. comms. Barry Mudge, PIRSA Farm Gross Margin and Enterprise Planning Guide
**Gross margin grazing value = DSE grazing days x (GM/DSE / 365)
Yes it is!
With current barley, wool and lamb prices, by converting 1 tonne of lost grain into sheep production, the gross margin for grazing is greater than the gross value of the grain lost (before production costs have been deducted).
This demonstrates that grazing offers great recovery value for grain losses and that grazing a standing barley crop can be a more profitable alternative than harvesting
What about canola?
Canola losses are harder to quantify and graze at this point. If the fallen canola seed germinates on a summer rain event it can provide valuable green feed, high in protein and energy. When grazed, canola shoots should be actively growing and not stressed to lower the risk of nitrate poisoning. Ensure the canola shoots are no more than 60% of the diet and provide access to high fibre feed; it does not have to be good quality, just high fibre like baled hay or straw or access to an adjoining cereal stubble paddock.
For more information contact Livestock and Farming Systems Officer, 03 5492 2787 or email@example.com.