Comparing the protein source and frequency of supplementation of forage intake, competitive feeding interactions, and nutrient utilization for beef cattle fed low-quality forage

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Use of forage that has been reserved for later use (stockpiled forage) and the use of crop residues that remain after cereal grains have been harvested allow beef producers to provide an out of season grazing option for their cattle. However, stockpiled forage, particularly native range, and crop residues are often low in crude protein. Feeding diets deficient in crude protein limits feed intake, digestibility of the feed in the rumen (the first part of the digestive tract for beef cattle), passage of feed out of the rumen, and overall digestibility of those feeds. Importantly, this crude protein deficiency can be corrected using feeds with a high crude protein content. Research in the United States has demonstrated that distillers grains, a byproduct arising from ethanol production, are a suitable supplement to correct for the crude protein deficiency that may occur with stockpiled forage and crop residues. They have also demonstrated that infrequent supplementation (every second day) can compensate for low quality forage equally as well as daily supplementation. While not investigated previously, providing the protein supplement infrequently may reduce competition for the feed at the time of supplementation as a greater quantity is fed on alternate days. While distillers grains are a suitable protein supplement, recent changes in processing of distillers grains (removing part of the the lipid) warrant further evaluation of this feedstuff. Additionally, the risk for mycotoxins in distillers grains may constrain the use of distillers grains as a feed source. In Canada, canola meal is a locally produced protein supplement known for its high quality as a protein source when fed to beef and dairy cattle. There is currently a limited amount of information regarding the use of canola meal as a supplement for cattle consuming low-quality forages. This study will evaluate the effects of using distillers grains with a low-lipid content in comparison to canola meal as protein supplements for beef cattle consuming low-quality forages. The study is expected to provide needed information on how supplemental feeding management affects feeding behaviour of beef cattle and to compare the effectiveness of canola meal and distillers grains with a reduced lipid content as protein supplements for beef cattle.