Limit Canola Hay in Feed Mixes

REGINA - Feb 10/03 - SNS -- Livestock producers are cautioned to include no more than 50% or 60% canola hay in livestock rations because of the risk of animals developing sulphur related ailments.

"Canola contains many sulphur compounds, some of which are converted to sulphates in the rumen," explains Bryan Doig, livestock agrologist with Saskatchewan Agriculture, Food and Rural Revitalization in North Battleford. "As with water containing high levels of sulphates, several feed-related problems can occur."

High sulphate levels in the rumen, for example, can cause copper deficiency and inhibit the absorption of selenium. Producers using canola as feed or silage should be providing trace mineralized salt containing copper levels of 2,500 mg per kg or higher, and selenium at 90 or 120 mg per kg. Minerals should contain sufficient levels of copper - 2,500 mg per kg or higher - and selenium at 25 to 60 mg per kg.

"The National Research Council for Beef Cattle recommends that the total dietary intake of sulphur should not exceed 0.4% dry matter. But sulphur levels of canola can range from 0.5% to 1.3% or higher. High levels of total dietary sulphur initially reduce feed intakes and lower rates of gain. As sulphur levels increase in the body, the production of thiamine (vitamin B1) is impaired, and scouring may become evident in affected animals. Thiamine deficiency may develop, especially in younger animals, and this can result in polioencephalomalacia (PEM). If left unchecked, death can occur."

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