Spatial variability of broiler litter composition in a chicken house

Broiler litter composition-estimated through its pH, water content, and concentration of total P, total dissolved P, molybdate reactive P, total C, total N, NH3-N, ammoniacal N, K, Ca, Mg, Na, S, Mn, Cu, and Zn-varied markedly according to the positions in the chicken house from where samples were taken. Variability was described by means of contour plots as well as univariate and multivariate analyses (principal components analysis). The evidence suggests that variation in litter composition was associated with the extent and conditions of its decomposition. The latter seem to have been influenced mainly by the interaction between management factors (maintenance of chickens in the brooder area and waterers operation), design attributes (ventilation system and building orientation), and birds' preferences. Results suggest that the degree of litter decomposition (indicated by the inversely related proportions of mineral and organic elements), increased from the area around feeders (17% water) through the area in the center of the chicken house (30% water), up to the area around waterers (55 % water). In the latter, however, anaerobic decomposition probably prevailed as evidenced by low pH and high NH4+ concentration. Decomposition also seemed more advanced in the brooder versus the nonbrooder area.