Managing the moisture content of litter requires a careful balancing act. Its importance cannot be understated as maintaining moisture levels of 20-40% serves as the basis for management recommendations on microbial growth, litter pasteurization and ammonia volatility.
Litter serves as a sponge—absorbing and retaining house moisture while minimizing dust. When you squeeze a handful of litter, it should compact, but then fall apart without excreting liquid. Litter moisture isn’t about the liquid on the surface, but rather the moisture content in the litter pack.
Too often the moisture equilibrium is lost and litter is too wet or too dry—both of which can cause significant health and performance issues. When moisture content is too high, the environment becomes ideal for bacterial replication, and ammonia remains trapped in liquid form and doesn’t flux off.
When litter is too dry—a condition we often see from late January to early March when outside relative humidity tends to be low—multiple bird health and litter management challenges arise.
Low Moisture Challenges
- Respiratory health. Address increase in late break air sac and bronchitis susceptibility increase.
- Ammonia control challenges. Ammonia volatility is often linked with wet litter, but in reality ammonia will flux off dry litter equally. The difference lies in the ability to control it due to the lack of moisture interface to interact with amendments. Most litter amendments require moisture to activate. If the floor or air is very dry, slow or no activation is experienced until birds start to drink or minimum ventilation is adjusted to allow relative humidity to rise.
- Proper litter pasteurization. In-house windrowing for microbial control requires a certain moisture level or the core windrow temperature will not reach temperatures necessary for effective pasteurization. Optimal moisture content is 30 to 50 percent, with a minimum level of 25 percent.
Properly managing moisture begins by understanding the variables that can impact it
- Heating source. Different heating sources will impact moisture; tube heat will keep air much drier while brooders put moisture back into the house during gas exchange.
- Understand the timing of moisture accumulation. Understand where and when moisture will accumulate. Larges accumulation of water in the floor happens in the last 3-4 weeks of the grow out cycle.
- Pay attention to weather patterns. Since outside humidity plays such an intricate role in house moisture, assess incoming weather to identify the ideal time to dry houses or leverage weather to increase moisture.
- RH management starts before bird placement. Moisture is cumulative. Use a RH meter before pre-heat and bird placement to assess moisture levels and prepare the ideal environment for chicks. Remember the role RH plays in coccidiosis sporulation. A minimum of 20-25% litter moisture content is required to ensure sporulation can occur. However, too much moisture can lead to excessive sporulation and an overwhelming challenge for the birds.