Such feeding will bring many benefits but it also carries the risk of grain poisoning.
Grain poisoning occurs when large amounts of starch are eaten and rapidly ferments in the rumen or first stomach.
This leads to the excessive production of lactic acid, which is absorbed into the animal’s body.
Hence the condition’s other name, lactic acidosis.
Grain poisoning may occur when:
- grain or pellets are introduced too quickly;
- there is a sudden increase in the amount of grain or pellets being fed;
- there is a change in type of grain or pellets being fed;
- there is insufficient feeding space leading to the dominant animals overeating;
- producers are not aware the same precautions need to be followed when feeding pellets; and
- there is accidental overeating due to storage areas not being sealed.
The clinical signs of grain poisoning usually become apparent within 24 to 36 hours after the initial access to grain or pellets.
In mild cases, cattle and sheep may show a lack of appetite and appear quieter than usual.
In more severe cases, cattle and sheep may show weakness, lameness, abdominal pain and diarrhoea ranging from porridge to water consistency, depending upon the severity of the condition, leading to dehydration. Grain poisoning can be fatal to livestock.
Reducing the animal’s access to grain or pellets and increasing the availability of roughage can treat mild cases.
More severe cases may need to be drenched with sodium bicarbonate to neutralise the lactic acid.
Severely affected animals are unlikely to respond well to treatment.
Following treatment, affected animals may develop hoof problems and lameness due to hoof damage caused by grain poisoning.
Like in so many conditions, the best form of treatment is prevention.
The key to prevention is to gradually increase the proportion of grain or pellets at a rate to which the animal’s body can acclimatise.
Feeding guidelines are readily available in drought feeding guides for sheep and cattle. Drought feeding guides are freely available from Agriculture Victoria’s website.
For more advice, contact your local veterinarian or Agriculture Victoria veterinary or animal health officer, or in NSW your Local Land Services.
— Dr Jeff Cave is an Agriculture Victoria senior veterinary officer.
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