Author
GREENE, L - TEXAS AGRIC. EXP. STN. | |
Cole, Noel |
Submitted to: Proceeding of Plains Nutrition Council Symposium
Publication Type: Proceedings Publication Acceptance Date: 9/5/1997 Publication Date: N/A Citation: N/A Interpretive Summary: This manuscript reviews current knowledge concerning nutritional and management techniques to decrease the accumulation and losses of nutrients from beef cattle feedyards and takes a futuristic look at technologies and management schemes that may be used in the future to decrease these nutrient losses. There are increased concerns about environmental quality problems potentially cased by excessive nutrient accumulation near beef cattle feedyards. These include the loss of nutrients by runoff into lakes and streams, by percolation into groundwater, or by emission into the atmosphere as respirable gases or dust particles. Currently, systems are available to limit these losses, however, additional progress will be needed in the future to develop improved waste management systems that are environmentally friendly, sustainable, and economically beneficial. Some methods that might be used in the future to control dust and odor include the use of feed additives, soil amendments, "green areas" around feedyards lagoon additives, improved feedlot surfaces, and dietary regimens to increase nutrient recycling. This may require that feedyards become more diversified operations that provide the outlet for their waste products. Technical Abstract: This manuscript reviews current knowledge concerning nutritional and management techniques to decrease the accumulation and losses of nutrients from beef cattle feedyards and takes a futuristic look at technologies and management schemes that may be used in the future to decrease these nutrient losses. There are increased concerns about environmental quality problems potentially caused by excessive nutrient accumulation near beef cattle feedyards. The nutrients of major concern are nitrogen (N) and phosphorus (P). On average, feedyard cattle excrete about 125 g of N and 43 g of P per head daily. Efficient waste management systems must be developed that are environmentally friendly, sustainable, and beneficial for feedyard owners and managers. From 3 to 20% of excreted N is lost in runoff from the feedlot surface. Only 10 to 20% of excreted N (7 to 15% of N intake) is collected in the manure. Similarly, 2 to 5% of P consumed is lost in runoff from the feedlot surface and 25 to 35% is collected in the manure. Few of the nutrients excreted by cattle leave the yard in dust particles and only 2 to 4% of the dust particles emitted by beef cattle feedyards have a mean aerodynamic diameter of less than 2.5 microns (PM2.5). Feedyard odors are comprised of at least 45 different volatile gases produced mainly via anaerobic fermentation of N, C, and S containing compounds in feces and urine. Some methods that might be used in the future to control dust and odor include the use of feed additives, soil amendments, "green areas" around feedyards, lagoon additives, improved feedlot surfaces, and dietary regimens to increase nutrient recycling. This may require that feedyards become more diversified operations that provide the outlet for their waste products. |