Reduction of nitrogen output from pig herds through better feeding : economical evaluation and effects of the new Common Agricultural Policy (CAP)

Abstract

In regions where intensive animal production is found, the management and disposal of manure directly affects the extent and the risk of water pollution by nitrates and air pollution by ammonia. As an alternative or complement to the treatment of effluents, solutions have been sought to reduce nitrogen pollution at its source of production. One approach that has been pursued has been to better adapt protein available in feeds to animal needs. In the context of the reformed CAP, this paper presents an evaluation of the cost of such a preventive approach to nitrogen pollution control. The results show that the CAP reform has introduced important modifications in the formulation of feed rations. A 1 to 1.5 point reduction in the protein content of feeds is estimated to result in a diminution of nitrogen excretion by pigs in the range of between .2 to .4 kg/pig. Further, it is shown that these results are very sensitive to the relationship between the prices of protein and energy. Modifications in the feeding strategy (number of diets) induce a decrease in nitrogen excretion in the range of 500 g/pig, as well as a reduction in the cost of the feedstuffs by 8 to 13 FF/pig (3-5%). However, this approach requires supplementary investments at the farm level for storage and distribution of the feeds. The improvement of the amino acid balance of the diet is generally associated with an increase in total feed costs. It is estimated that a reduction in nitrogen output by 500 g/pig would involve additional costs of 2 to 4 FF/pig. Jointly considering the benefits of improved feeding program and the improved protein balance, it is clear that nitrogen production can be reduced about 20 to 25 %, without substantilly increasing the cost of primary feed ingredients.