De-caking and litter conditioning are practices used to reduce litter caking by breaking it up or removing it from sheds, which improves friability at the litter surface. De-caking is a management practice that removes the caked layer from sheds and leaves the friable litter (especially when using a purpose-built litter de-caking machine). Litter turning and mixing (conditioning) is a mechanical process which chops the cake and combines it with friable litter. Both practices aerate the litter, which releases trapped moisture and gases (particularly ammonia). In cases where the moisture content of the litter is too high, caking may re-occur shortly after litter conditioning because the litter has lost the characteristics that allow it to be friable (Dunlop 2017).

Where the moisture content of the litter is too high, caking may re-occur shortly after litter conditioning because the litter has lost its friability.

De-caking is far more commonly used practice in the USA, where multi-use litter practices are widespread and where full litter clean-out may not occur for several years. This caked material will contain a greater manure component and less bedding material than spent litter removed during total cleanout. This material is potentially more valuable as an inorganic fertiliser due to it having higher nitrogen mineralisation rates following land application (Watts et al., 2012).

De-caking is conducted after each flock, with the cake separated from the litter by passing the cake and the dry litter materials over a grate. The grate allows fine materials to pass through and remain in the sheds, with larger aggregates of caked materials collected in a hopper for removal. Small quantities of fresh bedding material may be added to sheds prior to brooding to compensate for the amount removed with the cake (Sistani et al., 2003).

Ritz et al. (2017) recommend the removal of cake between flocks using de-caking, rather than litter conditioning. The removal of cake will get excessive moisture and manure out of sheds, rather than reincorporating it back into the litter. When wet caked material is not removed, it can contribute to more ammonia being released from the litter in the following flocks if the litter is re-used.

The removal of caked material rather than conditioning and incorporation may be a better management practice, as it removes moisture from the shed, and may reduce ammonia release during subsequent flocks when litter is re-used.