Fertilizing value of broiler litter: Effects of drying and pelletizing

The effects of drying and pelletizing on the properties of broiler chicken litter, obtained from a farm in northwest Spain, were investigated. The drying and pelletizing process reduced among-batch variability in dry matter content, electrical conductivity, urea N, and K, S, Na, Fe, Cu and Cd contents, but increased among-batch variability in total N, ammonium N, nitrate N, total P and pH. N form contents in the pelletized product could be estimated with reasonable accuracy on the basis of dry matter content. Cr, Cu and Cd contents were all significantly lower in the dried pelletized product than in fresh litter, whereas Pb content was significantly higher. The dried pelletized product is of course clearly preferable to the fresh product as regards storage and handling, however, our results suggest a need to optimize the production process with the aim of reducing possible contamination during manufacture, and of minimizing variability in N form contents, P content and pH.