Differences in soil, climate and socioeconomic conditions cause animal production to vary widely between European regions, notably in animal density and percentage landless farming. They have in common that animal products result from the cycling and redistribution of nutrients through soil, air, plants, animals and manure, with energy from photosynthesis or from the input of fossil energy as driving force. Nature of nutrients and rates of their conversion vary between and within cycle components, and consequently imbalances occur, causing undesired nutrient losses to or extractions from soil, water and air. Nutrients causing environmental concern are those containing excessive phosphorus (P), potassium (K) and nitrate (NO3-) contaminating soil and water and those losing the greenhouse gases carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) into the air. Successful and feasible interventions are to extensify, to reduce external inputs and to optimise. Maximum stocking density should not exceed 2.0 livestock units (LU)/ha. Reductions in external inputs of N, P and K are possible through reduction in fertiliser inputs and by reducing or applying compositional changes of dietary inputs. Optimisation at farm level includes implementing the nutritive measures mentioned above combined with an increased reproductive efficiency by lowering the number of parent animals. Animal manure should be treated as a commodity rather as a waste, with a tailor made composition to be achieved by nutrition or by fractionation. The recommended measures require legal and mental interventions, the success of which will largely depend on the quality of legislation and the acceptability of its implementation. (C) 2003 Elsevier B.V. All rights reserved.
- greenhouse-gas emissions