ARS | Publication request: Environmental impact of new feeding choices in the feedlot industry

Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: December 19, 2012
Publication Date: N/A

Technical Abstract: The feedlot industry is adapting to an economic environment that has fundamentally changed because of high corn prices. Developing strategies to improve the efficiency of feed utilization and reduce costs are important. Uses of agricultural commodity products for alternative fuels are rapidly increasing, resulting in an increase in the supply of coproducts. The replacement of concentrate grain with coproducts is appealing in finishing diets because of record high grain prices. Their utilization in livestock diets is complicated by a lack of information on the interactions with other ingredients in mixed diets. The evaluation of roughage concentration, and source in feedlot diets became more important in recent years because of the prolonged severe drought which occurred in the Plains. During such periods, traditional roughage sources like alfalfa hay and corn silage were not only difficult to procure, but extremely expensive. Typically, feedlot diets include between 8 and 9% roughage, which is more costly per unit energy than concentrate grain. As a result of the increased fiber in distillers grains, it is reasonable that dietary concentration of roughage could be slightly decreased when distillers grains are included in feedlot diets. Other coproducts are also more readily available as a result of the expansion of the biofuel industry. Glycerin is an energy-dense coproduct from soy diesel production that can be utilized by ruminant species. It is hypothesized that glycerin is primarily converted to propionate within the rumen, thus acting as a precursor for glucose synthesis. Coproducts such as glycerin can be included in feedlot diets as potential replacements for concentrate grain or roughage. The economical challenges present in today’s cattle feeding industry set the stage for very dynamic decisions on new feed ingredients. Recent research from our location suggests that cost of gain can be decreased by reducing the roughage level in finishing diets including distillers grains and additionally by replacing corn grain or roughage with crude glycerin in growing and finishing diets fed to feedlot cattle.