Reducing nitrogen pollution
from livestock

Reducing the excretion of NH3 and the generation of N2O by livestock

The use of protein-rich raw materials in feeds raises environmental issues. Although these raw materials make it possible to meet the requirements of animals with respect to the indispensable amino acids, they also cause large-scale excesses of amino acids which are catabolised by the animal and excreted as nitrogen in the slurry. These nitrogen-rich compounds in the slurry increase soil, water and air pollution through nitrogen by-products: nitrates, ammonium hydroxide, nitrous oxide, etc (Figure 1).

Figure 1. Mechanism of greenhouse gas (N2O) generation from livestock excreta

Low protein diets supplemented with amino acids can thus decrease nitrogen output into the environment and is officially recognised as one of the "Best Available Technique" (BAT) to decrease nitrogen excretion from livestock production (European Commission, 2003: "Reference Document on Best Available Techniques for Intensive Rearing of Poultry and Pigs").