Nitrogen consumption, utilisation and losses in pig production in France, The Netherlands and Denmark

In highly intensive pig production areas, manure disposal is a major proble m especially for nitrogen, because of water pollution by nitrates and air p ollution by gaseous ammonia emissions. The situations in three European cou ntries (Denmark, The Netherlands and France) were compared. On average, it was estimated that 17 to 19% of N intake is excreted in the faeces, and 45 to 50% in the urine, corresponding to a total excretion of 65 to 67% of int ake. The growing pig period has the major contribution to N excretion (72%) as compared to 18 and 10% for sows and weaners, respectively. The amount o f N in the slurry can be predicted precisely from the protein intake and th e performance of the pigs. It is possible to reduce N output through modifi cations in the feeding strategy. A better adaptation of the diets to each p hysiological or growing stage, and the improvement of protein quality throu gh the use of industrial amino acids are two complementary approaches for r educing N excretion. With these cumulative beneficial effects, it may be ex pected that N output in the slurry and in the atmosphere can be reduced by 20 to 30% through better feeding management. The research that is carried o ut in the different countries on the evaluation of protein availability in feedstuffs and amino acid requirements, and the development of computerised pig models, should allow further reductions of N excretion, and promote th e use of low protein feeding strategies in practice. (C) 1999 Elsevier Scie nce B.V. All rights reserved.