While in-house composting of litter may have some advantages, it can also create extra challenges in providing a proper environment for good respiratory health—namely the increase in ammonia once litter is spread back out and pre-heated for the next flock. Ammonia levels on windrowed litter are rarely below the 25 PPM needed to maintain tracheal health. In fact, windrowed houses have some of the highest ammonia readings in the field. Changes in litter amendment use are needed at placement and at turn-out to whole house to overcome the increased ammonia.
Why Does Windrowing Equal Higher Ammonia?
Temperature and surface area drive the amount and rate of ammonia released from litter. Ammonia release, or flux, will automatically increase as litter heats up to the proper brooding temperature of 90°F two inches deep at the litter core.
Increasing the surface area through windrowing dramatically increases ammonia release. It is not unusual for ammonia concentrations on recently composted litter to be 200-500 PPM prior to litter amendment application—a less than ideal environment. If this ammonia is not neutralized, flock health can suffer. All litter amendments applied at the standard rate of application in these conditions will be overcome by the increased ammonia challenge.
High Ammonia and Respiratory Health
Birds’ first line of defense against respiratory challenges is the mucociliary elevator of the trachea. As a bird inhales, bacteria, viruses, and other particles become trapped in the mucus that covers the cilia on the inner surface of the trachea. The cilia are small fibers that beat upward, in effect forming an elevator that lifts the trapped particles in the mucus out of the trachea where they can be removed or swallowed by the bird.
The most common cause of damage to the mucociliary elevator is ammonia. Ciliostasis or paralysis of the cilia can be seen with ammonia levels as low as 25 PPM (barely detectable by the human nose). Ciliostasis is commonly used as a measurement of protection against Infectious Bronchitis Virus by vaccine companies because when dust, bacteria, and viruses cannot be cleared adequately from the respiratory system airsacculitis may develop even when the bird has good immunity.
PLT® Use after In-House Composting
Coupling high ammonia from windrowed litter with a viral challenge is a sure recipe for trouble. When ammonia levels are elevated due to windrowing, the entire house needs to be treated with a litter amendment to neutralize this insult to the trachea as one of the most common causes of late airsacculitis is exposure to ammonia at move down.
In order to maintain air quality and ammonia levels below 25 PPM during brooding and through turnout, much higher rates of PLT® will be necessary to neutralize the high ammonia challenge. In general, PLT application rates need to be increased by 50-100% over the normal rate for the house type and litter age.
Houses that would normally use 75lbs./1,000 sq ft PLT® should now use 125-lbs. If your normal application rate is 100lbs./1,000 sq. ft. an increase to 150-200lbs./1,000 sq. ft. is in order to be able to counteract the high levels of ammonia being released when litter is leveled and pre-heated after windrowing. Whole house application of PLT will be necessary to protect birds from an ammonia insult at placement and at turn out.