Pig carcases could be disposed of via anaerobic digestion bringing 'significant benefits' to farms

Bio-reduction through anaerobic digestion (AD) could provide a viable solution for on-farm storage or disposal of porcine carcase material
Bio-reduction through anaerobic digestion (AD) could provide a viable solution for on-farm storage or disposal of porcine carcase material

The development of alternatives for on-farm disposal of fallen stock could be a 'significant benefit' to the industry as EU legislation is currently prohibiting farmers, according to researchers.

Research at Harper Adams University said bio-reduction through anaerobic digestion (AD) could provide a viable solution for on-farm storage or disposal of porcine carcase material (PCM).

This could reduce the costs of fallen stock collection on some farms, and reduce the movement of vehicles between farms – potentially improving bio-security and carbon emissions.

A second stage of research has now been completed at the university, jointly funded by Defra and AHDB Pork, to gather evidence on the efficacy and safety of the process.

Initial research established that the AD process could significantly reduce a number of particularly resilient pathogens in PCM, while at the same time generating considerable quantities of biogas, which could be used to generate heat or electricity.

EU legislation 'prohibits farmers'

However, the second stage of the project showed that AD alone did not sufficiently reduce pathogens and pre-sterilisation of the carcase material is needed before it goes into the AD plant.

The research also showed that pig slurry can be effectively utilised as a co-substrate (a product used alongside another material) to aid the process.

Dr Robert Wilkinson, Principal Lecturer and researcher, said: "The results of this project confirm that PCM can be effectively digested by AD, with high levels of biogas and CH4 production and carcase reduction.

"However, further research is required to test the stability of the protocol over a longer period of time and to evaluate the residue produced as a potential fertiliser or soil improver.

"In addition, the data obtained could be used to inform a desk-based study to design and evaluate the cost effectiveness of an on-farm pilot-scale system."

Sue Rabbich, Environment and Buildings Projects Manager for AHDB Pork, said: "Following the BSE epidemic in cattle, and other livestock diseases, EU legislation prohibits farmers from burying fallen stock on farm.

"Instead, they must be collected for disposal by approved methods such as incineration or rendering. The development of sustainable on-farm alternatives for storage or disposal of fallen stock could be of significant benefit to the agricultural industry."