This may largerly be dependant upon good management practise however it is my experience that straw based systems provide a significant improvement for the prevention of malodours and manure for land application? Please can you comment to support or provide evidence otherwise.
There is no straight simple answer as odour is the
result of many factors. Good practice and managment with attention to detail is
probably the biggest factor in minimising odour strength for pig production and
manure spreading.
There can be good and bad with both straw based and
slurry systems. When it comes to manure spreading then well-composted manure
will be less odorous than fresh or wet poorly stored manure. You can have slurry
spreading with minimal odour - spreading equipment is one key
component.
The old Defra Air Code goes into more detail about
minimising odour (more so than the new combined code), please have a look at
this and feel free to contact us again if you have more questions.
Defra Air Code: http://webarchive.nationalarchives.gov.uk/20081107164432/http://www.defra.gov.uk/farm/environment/cogap/pdf/aircode.pdf