Poultry litter management on many broiler farms is outdated and needs to be changed to match today’s grow-out conditions, said Blake Gibson, Jones-Hamilton Company, at the Poultry Production and Health Seminar.
Gibson said many growers manage their houses today the same as was done 30 years ago when used litter was replaced with new shavings between flocks. With today’s farms growing birds on built-up litter, new litter management practices are necessary, he said.
He presented an approach to managing built-up litter that limits mechanical stirring of the litter and triggers peak ammonia volatilization between flocks. Resulting advantages, he said, include controlling birds’ exposure to ammonia, while saving heating fuel and freeing up the grower’s time.
Litter impacts flock performance
Litter management practices are important, Gibson said, because they have a big impact on the profitability of the company and the farm.
“Not managing litter properly potentially costs a tremendous amount in performance. In some cases, one day of bad management – whether in poor waterline management or poor house ventilation – costs about 3.5% of a flock’s production. That is a pretty substantial cost,” he said.
Litter management has an impact on numerous performance factors, including feed conversion and disease conditions such as air sacculitis, E. coli infections, coccidiosis and footpad dermatitis.
Gibson talked about improving flock performance two ways – lowering harmful bacterial populations in litter by lowering the pH and reducing flocks’ exposure to ammonia by managing the level and timing of its release.
Managing the ecology of built-up litter
“If there is one concept to understand for the effective management of built-up litter it is litter ecology,” Gibson said. “Built-up litter, itself, is a living organism. It has its own life cycle of various living organisms, including both good and bad bacteria, which have nutrient needs.” Management practices, he said, are available that maintain a balance in that lifecycle and contribute to healthy, productive broiler flocks.
The role of pH in boosting ‘good’ bacteria
Gibson’s recommendations include managing litter’s pH, which plays a big role in the lifecycle and balance of the organisms there. The pH of built-up litter ranges between 7.8 and 8.2, which is a range where growth is rapid for many harmful organisms, including E. coli, Clostridium, Salmonella and Pasteurella.
Good bacteria, such as Lactobacillus, on the other hand, grow in a more-acid, or lower pH, environment. A shift to more of the beneficial microorganisms can be achieved, he said, when the litter’s pH is brought below 4.3.
Ammonia an insidious challenge
Ammonia can be an undetected factor in poor flock performance, according to Gibson. He told listeners that 19 points of weight loss is typically seen in 49-day-old broilers when ammonia in houses is at 20 ppm, and that level may easily be exceeded without it being detected by growers.
“Growers and production managers consistently underestimate ammonia levels in production facilities when they depend on their noses and eyes for detection,” he said. Most people don’t detect ammonia until it gets above 40 ppm, and some may not detect it at even higher levels due to constant exposure and a resulting desensitization.
At 40 ppm, ammonia can result in increased levels of air sacculitis and E. coli infections in the lungs of the birds.
“If we rely on our own senses to tell us that ammonia levels are high in houses, it is costing us a lot in performance,” he said. He recommended that growers invest in ammonia detection equipment.
Managing ammonia exposure
Where Gibson’s management recommendations are “outside the box” involves how ammonia levels are managed through decaking practices and ventilation techniques between flocks. The recommendations include the tried-and-true basics of good ventilation but deviate on points like when and how aggressively to decake litter and whether houses should be opened or closed between flocks.
When litter management begins
Timing plays an important role in several of Gibson’s management recommendations. Make an assessment of litter conditions when flocks are between four and five weeks old, and develop a plan to decake problem areas, such as under water lines, once the flock has been moved from the house.
Control the house environment
Keep houses closed tightly between flocks. He cited the following benefits of retaining the heat from the previous flock:
• The retained heat helps maintain the microbial balance in the built-up litter. Any shift in that balance impacts the next flock.
• Because heat in the floor increases for a time after the previous flock has been removed from the house, an increase in ammonia volatilization occurs while the house is empty of birds. It is advantageous to achieve this ammonia purge before the next flock of chicks is in the house.
• Conserving heat in the litter base saves on fuel needed to pre-heat the house for the next flock.
When to decake litter
The time to decake the litter is within 24 to 36 hours of when a flock has been moved out of the house. That’s when the house and litter base are at the highest temperatures.
“The objective is to hold that heat in the floor and continue the ammonia volatilization,” Gibson said.
Most growers today spend between two and three hours decaking a house from sidewall to sidewall, but that’s not necessary and is actually counterproductive, Gibson said.
He recommended minimal mechanical stirring of the litter. “The more the litter surface is disturbed, the greater the volatilization of ammonia and the greater the drying action,” he said. “There is a fine balance of moisture that is needed – ideally between 15% and 25%.”
Decaking machines should be run only in areas where caked litter exists. “The goal is to minimize the exposed surface area. If the litter surface doesn’t need to be disturbed, don’t disturb it,” he said.
Avoid creating fluffy litter, he advised. Not only is fluffy litter more readily rutted by live-haul equipment, fluffy litter conditions allow water to filter to the floor pad, which creates conditions that lead to greater ammonia production.
Elbow grease required
Some house areas do require special attention. Because decaking equipment won’t reach areas immediately adjacent to sidewalls and corners, growers should manually decake these areas – if caked litter exists there.
“The highest ammonia levels and bacterial populations occur in areas where caked litter is not cleaned out,” Gibson said. “Because birds tend to move to the sidewalls – especially when they are not comfortable – extra effort is required to remove any caked litter there.”
Growers should be spending only 45 minutes to an hour managing the litter in a house between flocks, which will allow them more time for preparing for bird placement, he concluded.
Continual evolution of litter management
“We have to think outside the box about litter management and try different scenarios,” Gibson said. “The cost of bedding materials is up about two-fold compared to five years ago, and those costs will probably continue to increase. So growers need to utilize litter for as long as possible and get the maximum efficiency from it. That means we have to be willing to make changes.”