Determination of Activation of Litter Amendment on Ammonia Control for Broiler Litter under WinterConditions

摘要

Inadequate moisture for activation of acid-based litter amendments has been a challenge for winter flocks when both relative humidity and litter moisture drop due to the dry colder air outside. A series of laboratory experiments were performed to determine the threshold environmental condition to activate aluminum sulfate, sodium bisulfate, a mixture of aluminum sulfate and sodium bisulfate, and an aluminum-based new litter amendment (new product) under dry condition during winter period. There was no significant relative humidity threshold for aluminum sulfate and water absorption rate of aluminum sulfate was less than 4%. The new product can absorb up to 23% of moisture from air and was more hydroscopic when air relative humidity was less than 45%. The relative humidity threshold for activating sodium bisulfate was approximately 45%. When the moisture content of built-up litter (one-year or older) is 25% or higher, aluminum sulfate can be applied at least 24hr before chick placement and activatedby keeping air relative humidity at 45% or higher for 48 to 72 h during brooding. An application rate of488g/m2 can cut ammonia (NH3) emission by 50% over the first week of the brooding. When the moisture content of built-up litter is 20% or lower, aluminum sulfate and sodium bisulfate with a mixing ratio 80:20 by weight can be co-applied at the rate of488g/m2 and activated by maintaining air relative humidity at 45% or higherfor 72 h during brooding. The new product can be used to control NH3 with thesame application rate for aluminum sulfate without inclusion of sodium bisulfate. When litter is windrowed, the house should be vented for at least 48 h before aluminum sulfate is applied.