Experiment were conducted to study a method of dead piglets disposal by homogenization of the carcasses that could be than disposed in the liquid manure system of the production unit. Three experiments were realized. In Exp. 1, ground piglet carcass homogenized was added to manure to increase its original dry matter (DM) content of 1, 2 or 4%, control was kept for comparison. After 90 days, the dry matter content of the manure was verified and no statistically significant differences in DM were fund among the 3 manure that had or did not have received ground piglets carcasses. In Exp. 2, tanks were filled with liquids manure and ground piglet carcasses were added to the DM of the manure by 2%. Pseudorabies virus or Salmonella antum (S. antum) was added to the manure; pseudorabies virus was detected at 6 hours but not at 12 hours after the inoculation. 21 days after the incubation, S. antum could not be detected anymore in any of the tanks. In Exp. 3, a piglet pathogen mixture (S. antum and T1 coliphage) was added to liquid manure. The manure treated was then applied to crop land. Tested were done to observed the presence of the coliphage and S. anatum which could not be detected by day 20 and 56 respectively after the manure had been applied. The addition of ground piglet carcasses had little effect on the D.M. content of the manure and did not present problems with DM accumulation in the storage structure. Considering the lifetime of the pathogen in the soil, this method did not promote the distribution of swine pathogens in the environment.
More work is needed to identify the stored manure conditions that lead to pathogen control. This type of disposal could not be interesting for larger pig carcasses as the loading of the manure system would be increased. Further experiments are needed to evaluate the behavior of other common pathogens not studied here. The experimental method presented here is not an approved carcass disposal system in Minnesota and written permission were required from the Minnesota Board of Animal Health.