Broiler house litter processing by anaerobic digestion using enzymes
Sawdust is used as litter for broiler chickens. Mostly they are taken from the treatment of low-value deciduous trees. Keeping broilers for 40-50 days on a litter of sawdust, all the time, absorbs moisture well and mixes with bird droppings. When the broilers are moved to the slaughterhouse, these littered manures are removed from the barn and stored in stacks. They can be used to fertilize fields but only once or twice a year when the fields are fertilized, so they need to be spread over large areas and must be covered due to unpleasant odors. The other alternative is to use this manure with litter to produce energy, preferably biomethane. Sawdust is rich in lignin, cellulose and hemicellulose and is therefore slowly and incompletely broken down by bacteria. This study investigated the effects of the use of the enzymes alpha amylase and xylanase as well as the biocatalyst Metaferm on the mixture of bird droppings and sawdust actually produced in broiler houses. The 14 bioreactors of the laboratory were filled with raw materials and the appropriate additives were added. An average of 0.349 Lg-1dom methane was obtained from bioreactors where alpha amylase was added, but 0.368 Lg-1dom methane was added to xylanase. From the bioreactors where the biocatalyst Metaferm was added average yield was 0.329 Lg-1dom of methane. Addition of enzymes improved methane production, but the addition of biocatalyst Metaferm showed no improvement compared to control bioreactors.