Litter can be re-used for multiple grow-outs, as opposed to the most common practice in Australia of using new bedding for every growth cycle. As such, litter re-use reduces the requirement for new bedding materials. Litter re-use may be partial, where fresh bedding material is used for brooding, or full re-use, where brooding and grow out occur on re-used litter.

Litter re-use is widespread in some countries (e.g. USA), but is not commonly practised in Australia. When it is, it is generally only partial re-use and only for 3–5 growth cycles. In the USA, litter is sometimes re-used for several years, with full re-use for more than 15 growth cycles.

After a growth cycle, litter is generally heaped into piles or windrows (see Figure 12) before being re-spread in sheds. During this time, the litter should undergo a partial composting process called pasteurisation that generates heat via microbial activity. This in turn acts to kill pathogens and viruses that may be present in the litter. However, the effectiveness of this can be constrained by the time available between growth cycles. With partial re-use, new bedding is spread in the brooding area prior to placement of the next growth cycle. Re-use generally requires a longer break between growth cycles for the pasteurisation process to be effective. This can impose additional costs on the production system, including the need to vaccinate chickens for Marek’s disease. It may also result in fewer growth cycles due to the increased downtime between growth cycles.

Re-use will generally require a longer break between growth cycles than single use to allow sufficient time for the pasteurisation process to be effective.

In Australia, it is estimated that 86% of meat chickens are reared on single-batch litter, with the rest on partially re-used litter (rather than full re-use, like the USA).

Growers tend to have contractual and/or planning approval conditions that dictate that their litter is managed as single use. Furthermore, a survey of growers identified that re-using litter may make it harder to comply with accreditation schemes and there is a perception that it will compromise meat chicken performance, welfare and health, as well as increase ammonia and odour emissions and impacts. This may also lead to increased management costs (Watson & Wiedemann, 2018). Although there is the potential for these problems to occur, the risk can be reduced with appropriate management.