Sampling Broiler Litter: How Many Samples Are Needed?

Abstract

Poultry litter can be sampled from chicken house floors, storage piles, or at cleanout. Existing guidelines typically advise to obtain a composite sample from an arbitrary number of subsamples that can be taken randomly or systematically. If nutrients in poultry litter differ in the variability of their concentrations, the number of subsamples needed to obtain reliable analytical results should be a direct function of their variabilities. Our work documented the variability in the concentrations of nutrients in broiler litter, when samples were taken from different parts of a commercial chicken house and from the trucks at cleanout. Additionally, using conventional statistical and computer-intensive random resampling methods, we calculated the number of subsamples needed for the mean concentrations of components to be within specified ranges from the experimental mean 95% of the time. The results showed wide differences in the variability of nutrient concentrations and the advantage of sampling after the broiler litter has undergone some degree of mixing, as may take place during cleanout.