Why important: Wet litter and caking may be caused by the interaction of a variety of factors. Maintaining litter in a friable state will enhance moisture removal from sheds when combined with effective ventilation.

Outcome: Wet litter in sheds is minimised and the litter remains friable.

Performance measures: Daily vigilance, including inspection, monitoring, record keeping and positive actions to reduce the incidence of wet litter.

Best practice actions:

Shed and infrastructure design and management
• For new sheds, ensure floors remain dry through correct design, where sheds are built above the outside ground level.
• Provide adequate drainage outside sheds to direct stormwater away from sheds as quickly as possible following rainfall.
• Adequately compact floors to prevent seepage from the ground. Do not assume that laying concrete floors will enhance litter management and reduce the incidence of wet litter. Concrete floors are less forgiving and may require additional management during the grow-out cycle.
• Ensure the roof and walls of sheds are sealed (other than the ventilation system) to prevent rain and surface water from entering.
• In areas of sheds prone to rising damp, consider laying concrete floors and installing guttering that directs water away from sheds.
• Flush drinker lines between growth cycles to remove slime and scale. This will help maintain correct pressure and reduce spillage.

Ventilation and cooling system
• Maintain and operate foggers to avoid the formation of coarse drops (those that fall to the floor of sheds). Mist produced by foggers should evaporate before reaching the floor.
• Where conditions allow, minimise the use of evaporative cooling and foggers to minimise relative humidity within the sheds. Attempt to achieve 40-60% RH to accelerate litter drying. When relative humidity is getting close to 60%, the ventilation rate should be increased.
• In cold and/or wet weather, operate the ventilation system in a manner that avoids moist incoming air condensing on the floor near inlets. Do this by combining air flow rate and heat (either from the birds or heaters) to reduce relative humidity in the sheds and accelerate drying.
• Ensure sheds are tight and have sufficient static pressure to get sufficient air mixing to maximise litter drying rates.

Bird health
• Inspect manure at least daily for incidence of watery droppings. Alltech have an example of a chicken faecal chart. Identify the cause of the problem promptly and resolve the issue. This may require consultation with the processor.
• Monitor chicken health daily and ensure any digestion problems are promptly identified and reported to the processor if necessary.

Meat chicken stocking density
• Do not stock birds at rates which exceed the limits of any regulatory approval/licence, welfare codes, voluntary accreditation schemes (to which the farm subscribes) and processor/integrator requirements.
• Check birds at least three to four times a day to ensure they are not congregating to particular areas (e.g. in front of cool pads). Monitoring will need to be increased during hot weather. Uneven bird distribution leads to uneven manure load, which can contribute to areas of wet litter.

Water supply
• Check drinker height daily to ensure it is the correct height for chickens.
• For nipple drinkers:
– set height at chicks’ eye level for the first few hours of age
– In the early stages of brooding, adjust drinker height to just above head height. After this, maintain height above chicks’ heads to ensure they are reaching (not straining) to reach the drinker and their feet are always flat while drinking. If they are turning their heads to the side while drinking, it will cause spillage.
– adjust pressure so there is a droplet of water suspended from the nipple.
• Check of the flowrate and pressure of the drinker system at least daily to ensure it operates as per manufacturer specifications.
• Perform a high-pressure flush on water lines between each flock and after adding supplements through the medicator.
• Ensure water lines are made from material that is resistant to scale and biofilm build-up.
• If biofilms are detected or suspected in the water distribution system, sanitise the water line with approved chemicals.
Inspect drinker lines, drinkers, cooling pad collection trays, foggers and other plumbing at least daily to identify leaks and repair if found.

Water quality
Analyse drinking water annually to ensure it meets the health and optimised performance requirements of the chickens. Details of water quality requirements can be found in the AgriFutures Australia publication ‘Industry best practice manual for water quality management and sterilisation on-farm’ (Watson et al., 2020).

Litter inspection
• Inspect litter conditions daily in each shed via sight and feel to ensure the litter is friable, with particular emphasis on likely high-moisture areas, such as around the air inlet, under drinkers and feeders, and near walls.
• Inspect litter depth daily and ensure it is even throughout the sheds. Minimum litter depth is generally at least 50 mm, but this may change based on the litter type, stocking density or accreditation requirements.

Litter maintenance
• Use mechanical conditioning to maintain friability, reduce caking and mix areas of wetter litter with drier litter. Mixing wet and dry litter may be useful to reduce the cohesiveness of the litter particles and prevent compaction and future caking. Breaking up wet and caked litter without adjusting ventilation and/or heating may not be effective or sufficient to prevent caking from rapidly re-occurring.
• Choose an appropriate time of the day and weather conditions to perform litter conditioning:
– to avoid odour impacts if conditioning releases additional odour
– to allow for higher ventilation following litter conditioning to remove ammonia
– to allow for higher ventilation following litter conditioning to maximise the removal of water from the friable litter and reduce the likelihood of it becoming cohesive, compacting and allowing cake to reform.

Litter condition assessment
Conduct daily inspections of the condition of the litter in three different areas of the sheds (the fan or non-silo end, middle, and the cool pad or silo end). Record the condition of the litter based on the nine descriptors below. Detail any corrective actions undertaken.
Dry and friable: No action required unless dust issues, may require conditioning to improve consistency.
Moist and friable: May require conditioning to improve consistency.
Dry and flumping: May require conditioning to improve friability
Wet and friable: Will require ventilation to remove excess moisture as it will compact quickly.
Moist and clumping: Prone to caking, so will require corrective actions such as conditioning, additional ventilation and heating.
Dry and caked: Will requiring mechanical conditioning to break the cake, as chicken excreta will remain on the surface. Additional ventilation likely required to extract ammonia that is released.
Moist and caked: Will requiring corrective action in the form of mechanical conditioning to break the cake. Will require additional ventilation to remove ammonia that is released.
Wet and clumping: Will require corrective action that includes adding dry friable litter to absorb moisture, as well as mechanical conditioning and ventilation to remove moisture and ammonia.
Wet and caked: Will require immediate corrective action that includes adding dry friable litter to absorb moisture, as well as mechanical conditioning and ventilation. This wet and caked litter may require removal and replacement with dry litter if the condition cannot be rectified.