Submitted to: Symposium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 12/15/2005
Publication Date: 1/5/2006
Citation: Powell, J.M. 2006. Enhanced use of feed and manure nutrients in animal agriculture. In: Visions for Animal Agriculture and the Environment. The John M. Airy Beef Cattle Symposium, January 5-6, 2006, Kansas City, Missouri. Available: www.iowabeefcenter.org/content/Airy/POWELL%20Abstract.pdf Interpretive Summary:
Technical Abstract: Whole-farm nutrient balances and animal:cropland ratios are used to asses overall pollution risks of livestock farms. These whole-farm indicators cannot address, however, how nutrient management in one production component (e.g., feed) may affect nutrient cycling in other production components (e.g., soils and crops) and the relative impact of each component's management on the environment. Many livestock operations rely on inexpensive nutrients so they are often used luxuriously to assure highest yields. Nutrient rich diets are recommended to maximize animal production and to maintain good animal health and reproduction. Manure, fertilizers and in some areas legume-fixed-nitrogen are used to maximize crop yield. This paper addresses integrated nutrient management on livestock farms to reduce nutrient surpluses and risks of environmental contamination. Nutrient use can be reduced without losses in productivity through a closer matching of livestock and poultry diets to animal nutritional needs, and by increasing the digestibility and bio-availability of nutrients in feed. This maximizes feed conversion into products (e.g., eggs, meat and milk) and minimizes nutrient loads in manure. In some cases, manure transport for land-spreading can be made easier by reducing water use during manure collection and storage. Cost effective methods of manure handling, treatment and storage are available, although adoption is very dependent on farm size and planning horizon of producers. Knowing nutrient concentrations and availability in manure can enhance effective manure nutrient recycling through crops. The use of decision tools can be effective in integrating nutrient use across crop and livestock production components. Attempts to improve nutrient management must acknowledge the real and perceived risks of nutrient utilization by engaging producers, their feed and fertilizer consultants, and policy makers in critical assessments of key factors that affect nutrient transformation and loss, and how these factors may be managed more effectively to enhance profitability, reduce environmental impacts, and contribute to rural livelihoods.