Animal production and European pollution problems

Environmental pollution from agricultural practices is of major international concern. To control agriculturally derived pollution, legislation is being enacted which both restricts agricultural activity and penalises farmers for exceeding limits related to waste disposal. Pollution relates to the contamination of land, water and air, and exists in the micro environment within livestock housing or the macro environment on and surrounding the farm. Two of the main sources of pollution of agricultural origin are nitrogen (N) and phosphorus (P) in excreta. Ammonia originating from the N in slurry, is a volatile component which adversely affects the health of stock people and the productivity of stock occupying the buildings. N and P in manure and slurry contribute to the build-up of these elements in the soil and via leaching, the pollution of water courses. Solutions exist to reduce the N and P excreted by livestock. Feeding systems which accurately supply the nutritional needs of pigs and poultry at different stages of growth and the use of feed additives such as enzymes which contribute to improved feed utilisation, all reduce excretion of N and P. Increased growth rate achieved by using either growth promoters or genetically imroved livestock also contributes to a reduction in N and P excretion. Major efforts are required to adopt all best available technologies capable of reducing N and P excretion from agricultural practices before restrictive legislation is enacted to control the problem.