Gippsland - How Now Gippy Cow
February 2011 Edition
How to use rain-hit grain
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T his year’s rain-affected grain harvest poses opportunities but also risks for dairy farmers, so Dairy Australia has updated its website advice to help farmers buy and feed weather-damaged grains.
Advice from Dairy Australia’s Grains2Milk program is now available at www.dairyaustralia.com.au/damaged-grain Dairy Australia Grains2Milk program leader Dr Steve Little said unseasonal rains would see a lot of shot and sprouted feed grain in the marketplace. “Dairy farmers are asking how its nutritional value compares to sound grain, how well it will process, and how to feed it safely.”
Farmers should be aware that weather-damaged grain is not a major issue for dairy cow nutrition. Most studies in cattle indicate the nutritional value of shot and early sprouted grain equals or even surpasses that of sound grain. “It does not significantly affect animal performance or feed conversion efficiency,” Dr Little said.
“However, shot and sprouted grain is more rapidly fermented by the bugs in the cow’s rumen, so this may increase the risk of ruminal acidosis in more digestible types of grain such as wheat. Buffers and other measures might therefore be needed to manage this risk.
“It’s worth knowing the test weight of a given type of grain is not a direct indicator of its nutritional value. Expect shot and early sprouted grain to have a slightly lower test weight than sound grain. However, be wary of grain more than five kilograms/hectolitre below the relevant 2010/11 Grain Trading Australia (GTA) feed grain standard, as its starch reserves may be depleted and energy value reduced.”
Grain should also be checked for levels of weed seeds such as Heliotrope (Potato weed) which produce toxins and may be more prevalent in this year’s grain harvest. These should be below the maximum number of seeds stipulated in the GTA standards for all grades of wheat (maximum eight seeds per half litre) and for feed barley (maximum four seeds per 100 grams).
When considering whether or not to buy a particular parcel of weather-damaged grain, Dr Little said dairy farmers should also check its moisture content and look for any signs of mould. “High moisture, shot and sprouted grains are more susceptible to mould growth before harvest or during storage,” he said.
“Various types of moulds produce toxins, called mycotoxins, which can be harmful to cow productivity and health. Any mouldy grain (or fodder) should therefore be treated with caution.”
Farmers should be wary of grain higher than the maximum GTA standard for moisture of 12.5 per cent.
“While it may look okay, it is more likely mould will grow during storage, and it will also be more prone to insect infestation,” Dr Little said. “You can be confident grain drawn from a bulk handling facility or stockfeed company will be below the maximum moisture limit of 12.5 per cent. But if grain has been stored on-farm, buyers will need to check moisture levels.”
Dairy farmers should carefully inspect each grain load for moulds, insects, foreign objects and weed seeds, then store it in dry and well-aerated conditions to avoid the growth of moulds.
“When feeding weather-damaged grain, it should be introduced into the ration slowly over several days while monitoring for any feed rejection, drop in milk production, milk composition or changes in cow health. Ideally, limit weather-damaged grain to 5 kilograms per cow per day until you are confident it is okay.” Dr Little said. “Continue to monitor for decreases in production and any changes to the health of the animals. As test weights of different grains vary, ensure your grain feeding rates per cow are always calculated by weight, not volume.”
Grains2Milk is one of the many examples of the dairy service levy at work. For more information on this and other levy investments visit www.dairyaustralia.com.au
