Odor emission from mixtures of ground swine carcass material and liquid swine waste

Mixing ground swine carcasses with the manure waste stream is a new concept currently being researched as an alternative carcass-disposal method. A co ncern has been raised with this method regarding increased odor and hydroge n sulfide emissions. Four pairs of 750-L (200-gal) polyethylene tanks were filled with swine waste and ground swine carcass material. Each pair receiv ed carcass material at the rate of 1%, 2%, or 4% (dry-matter basis) of the swine waste or received no carcass material (control). Odor analysis was de termined using a dynamic olfactometer Hydrogen sulfide gas concentration wa s determined using a Jerome(R) meter Statistical analysis was performed ove r the complete data set and in numerous subsets. There were no significant differences in odor unit or hydrogen sulfide concentration across any of th e four treatments. The data suggests that ground carcasses can be mired int o the manure stream at a rate up to 4% (dry-matter basis) without significa ntly increasing odor emission above existing swine manure emission, as indi cated by odor unit and hydrogen sulfide concentration. However a more reaso nable upper limit of inclusion might be 2% carcass material (dry-matter bas is), based on analysis of the air samples collected five days after the ini tial addition of carcass material to swine waste.