Poultry Litter Moisture: In Control or Out of Control?
You can have too much of a good thing. Yes, poultry litter needs moisture for optimal functionality, but too much can cause problems. Yes, built-up litter should be managed to control moisture, ammonia and pH, but overworking litter can cause numerous challenges.
When it comes to moisture content of poultry litter, Dr. Joey Bray prefers not to talk in terms of too wet or too dry. Instead, he asks the question: Is your poultry litter moisture in control or out of control? At a service tech training seminar in North Carolina, Bray focused on the extremes of poultry litter management, asking the question what happens when we take things too far in one direction?
“Optimal litter moisture is 20-25% and outside of that range you run into challenges,” shared Bray. Below 20% moisture, litter becomes dusty. Ventilation pulls that dust, and potential contaminants, into the air, increasing the chances of birds developing respiratory issues such as air sacculitis. For complexes using a cocci vaccine, litter moisture below 20% can also inhibit the efficacy of vaccination since low litter moisture content inhibits sporulation and prevents cycling.
However, litter moisture above 25% can also cause a host of problems. Excess moisture will increase ammonia generation and bacteria load. “Bacteria need moisture to replicate, so houses with moisture levels above 25% are going to see heavier bacteria loads.”
High litter moisture content can also cause litter to stick to the footpad of birds, which can cause discomfort and predispose them to bacterial infections and reduced mobility. Proper moisture control helps prevent the development of footpad lesions, ensuring better welfare and performance.
Bray went on to discuss the role of litter depth in that equation. “Maintaining the appropriate litter depth is crucial, with a target depth of around 4 to 6 inches.” This depth allows for sufficient cushioning, insulation, and absorption capacity without compromising airflow within the house. At appropriate levels, litter depth can help decrease moisture levels, improve paw quality, and keep ammonia levels low for better bird health and performance.
But how do you manage litter depth in today’s environment where built-up litter has become the norm? Ideally, how often should houses be cleaned out?
Bray shared that built-up litter is ok for about two to three years, but then often becomes less useful as the amount of waste increases. “When we add shavings, we’re adding carbon to the floor while each flock adds nitrogen to the floor. If we continue to add nitrogen but not carbon, the ratio becomes unbalanced and will result in higher ammonia production.”
The imbalance will also impact the ability to windrow, making it more difficult to reach the target temperature for effective pasteurization. Over time, the process of working the litter without adding carbon will decrease the litter’s particle size and its moisture holding capacity. Smaller particles stick to the footpad of birds more easily, potentially decreasing paw quality.
Bray closed with a focus on the key points of litter moisture management right before bird placement. “Pre-heating is crucial before chicks arrive.” Not only will pre-heating volatilize more ammonia out of the litter, it will also pull moisture out too.
A common pitfall Bray discussed was a failure to ventilate during pre-heat due to a common misconception that you’re losing valuable heat in the process. “We must remove the atmospheric ammonia that’s purged during pre-heat for the health of the house, the birds, and the efficacy of the litter amendment. Seeing a fog or haze in the house after PLT application is like seeing dollar signs coming out of the house.” That’s because a fog indicates that PLT is reacting with the atmospheric ammonia that wasn’t purged.
Appropriate ventilation during pre-heat followed by a PLT application at a sufficient rate for your ammonia challenge will maximize the efficacy of the product well into the flock.
Joey Bray, Ph.D., Technical Support Representative in the Agricultural Division, delivers education to audiences across the broiler industry. Dr. Bray has a 20+ year history in the poultry industry, serving on numerous poultry science management committees, in key roles at Stephen F. Austin State University, and driving research on various feed additives, poultry health products, nutrition solutions and environmental stewardship. Most recently, Bray’s research has focused on the evaluation of broiler performance.