Influence of in-house composting of reused litter on litter quality, ammonia volatilisation and incidence of broiler foot pad dermatitis

Abstract

1. The objectives of this study were to evaluate the residual effects of two windrow composting methods for reused litter on its quality (pH, moisture, ammonia), ammonia (NH₃) volatilisation and the prevalence (scores 0–4) of foot pad dermatitis (FPD) and hock burn (HB) on d 1, 7, 14 and 21 of age in broilers. Litter was allowed to compost for 8 d within a 14-d interval between flocks.

2. The composting methods studied were with or without a PVC plastic sheet. The same procedures were applied for three consecutive flocks, with litter initially having been used for 12 flocks. Data were analysed with a mixed model of repeated measures of day, with main effects and interactions of day, composting method, litter age (block) and house nested within method.

3. At d 1, litter NH₃ and NH₃ volatilisation were higher in the covered litter method. Litter moisture increased to 45.3% as broilers aged. The incidence of FPD also increased with age. No signs of HB were found in any bird throughout the trials.

4. There was no effect of litter composting methods on the prevalence of FPD or body weight at any age.

5. Litter moisture should be controlled to avoid NH₃ volatilisation reaching critical levels. Windrow composting of litter with a PVC plastic sheet may not be required when considering the broiler housing environment.

ACKNOWLEDGEMENTS

We thank the Graduate Program in Agroecossistemas of Universidade Federal de Santa Catarina, for financial support. MJH was supported by CNPq (PQ 308919/2009-2). Rosangela Poletto was supported by CAPES/Reuni. We are also grateful for the support from the slaughterhouse and the broiler grower.