[Digestion] Use of Solids from Thermophilic Digestion for DairyBedding

[Amy and Jim Rankin]

Tom,

No experience with digested solids, but separated raw manure solids that 
have been allowed to "heat" in a pile have been used as bedding with varying 
degrees of success depending on climate and seasonal effects.

The problem with all types of organic bedding is that though they may be 
quite "clean" from a bacteriologic standpoint, they support rapid growth of 
contaminating organisms within hours after placing in the stalls.  Perhaps 
the most successful attempt at limiting the problem associated with this is 
to have the bedding too dry to support growth (kiln dried sawdust as an 
example).  This is only a temporary solution, because even high quality kiln 
dried sawdust will have similar bacterial numbers to fresh manure within 
several days after placing in the stall.  Various other "sanitizers" have 
been tried including slaked lime and fly ash I believe and while the 
dessicant properties of these materials have been good, there have been no 
real clear cut positive results from their use or widespread acceptance. 
There was one trial with the ash in varying proportions from 100% ash to 
100& separated manure solids with results essentially improving with 
increasing % of ash.

Sand has emerged as the clear best choice as a bedding material whenever 
it's use is not precluded by some other factor.

Hope this helps.

Jim

James R Rankin, DVM
Cedarcrest Farms, Inc
Faunsdale, AL USA
> A North American company has proposed a thermophilic digester for dairy
> waste. They say that after dewatering the solids can be used as bedding in
> place of the sawdust that is now used.
>
> Is anyone actually using 100% thermophilic digestion solids as bedding in 
> a
> dairy?
>
> I have heard that solids from thermophilic digestion are difficult to
> dewater and consequently have an odor problem. Does anyone have experience
> with thermophilic digestion of dairy waste and use of the solids as 
> bedding?
>
> Thanks
>
> Tom Miles
>