As fall progresses, many growers find themselves fluctuating between the heat removal needs of summer flocks and the moisture control needs of winter ventilation. Fall temperatures, particularly in the southeast, can be cool at night but high enough to require heat removal in the afternoon.
There’s often a temptation to restrict ventilation in the evening without regards to relative humidity control. When this happens, moisture accumulation becomes a problem and can increase to the point where young chicks become too cool and litter begins to cake.
Another critical step in preventing wet houses come winter is removing a sufficient amount of moisture from the litter while the house is empty with a complete and thorough litter curing process.
Litter Curing: Manage Litter to Reduce Winter Moisture
To get houses off to a good start for winter brooding, follow these quick tips to reduce litter moisture:
1. Begin the curing process: As soon as live haul finishes catching birds in a house, shut that house up tightly to retain heat. Run a tunnel fan about 5 minutes at the end of every hour during daylight hours ONLY IF the house begins to sweat.
2. Check litter condition: Turn up the lights and walk the entire length of the house noting the location, depth, and character of the caked litter to understand how well your minimum ventilation and directional airflow programs were able to control humidity during the last flock. Make note of areas where maintenance may be necessary.
3. Get informed, then de-cake: Use the information on litter condition to properly set the de-caker or housekeeper. Set the blade just deep enough to get under the cake without disturbing the litter underneath. De-cake the house as soon as possible to allow the litter enough time to cure properly.
4. Don’t over de-cake (or till): Run the de-caker only in the areas of the house with cake, don’t “fluff” the litter by running it down to the floor or sidewall to sidewall. Doing so would release large amounts of ammonia that will not finish curing before the next flock arrives.
5. Time to cure: After de-caking, close the house back up tightly to allow the litter to cure. Floor temperatures should remain constant and separate from the influence of outside weather conditions. Run just enough fan time to prevent condensation inside the house.
6. Pre-heat: 48-72 hours prior to chick placement, turn on all brooders to 92-93°F, keeping houses closed tightly. This is necessary to get the deep moisture out of the litter. If you skip this step, moisture will quickly build at the litter surface once chicks are placed. That means litter will cake easily, chicks will be uncomfortable and gut health will suffer.
Running a short pre-heat time in a misguided effort to save fuel will not warm the house and the litter properly, and it will get wet quickly during the next flock. Birds will feel the impact of cool temperatures at the litter core and performance loss and mortality is the end result, not fuel savings.
Curing litter is like curing corn or concrete. It takes a sufficient application of time and temperature to get a good, even cure. The higher the temperature, the better and more evenly the moisture will be driven out from the litter. Properly cured litter will be able to handle the increases in moisture and relative humidity inside the chicken house that winter weather brings.