Tuesday, May 9, 2017
How to mitigate dust and ammonia in cage-free houses.
Cage-free housing is the new trend of raising poultry according to animal welfare experts,the birds need to be free to roam and stretch for your production to be considered humane. The problem however with this humane method is the amount of dust generated resulting in poor air quality in the house which posses a health challenge to flock and workers. Dr. Hongwei Xin, director of the Egg Industry Center, spoke about the results of research surrounding devices and methods designed to mitigate airborne pollution inside cage-free layer houses and emissions coming from them. The egg industry shift from conventional cages and enriched cages to cage-free operations,means more bird activity inside the house leading to increased airborne pollutants like dust and ammonia. Birds are moving around in litter areas – scratching, foraging and dustbathing – as well as flapping around the house stirring up dust. The hen’s freedom to move, and evacuate waste, wherever she pleases is another challenge. This means the manure belts in houses are no longer as effective as they once were in collecting and drying waste to simplify disposal and reduce ammonia emissions. Reducing ammonia through feeding and management, according to research the following were deduced with implementation yielding positive results. 1) Reducing dietary protein: By reducing dietary proteins by about one percent and maintaining nutritional balance in the feed, farmers can reduce ammonia emissions by about 10 percent. Dietary fibers reduce the pH value of manure, meaning less ammonia is mobilized from the manure. 2) Adding dietary fibers: Adding fiber, like wheat middling and soy hull, can reduce emissions from layer manure between 40 and 45 percent. 3) Adding supplements: DDGS, or distiller’s dried grains with solubles, and EcoCal, a proprietary feed additive designed to control ammonia emissions, can work as well. A study with a 10 percent DDGS feed mixture dropped ammonia emissions by 14 percent and a 7 percent EcoCal mixture reduced ammonia by 39 percent. Beyond feeding, drying manure on the belts is important to reduce the level of ammonia in the air. This can be done with air circulating over the belts, but that comes at the cost using the exhaust air to dry manure may be a cheaper way to provide the needed airflow. 4) litter moisture must be kept in check as well to keep ammonia levels down. This is a potential double-edged sword, however, because drier litter creates more dust.The wet litter gives off ammonia and cakes, creating numerous health issues for the birds. Ideally, the litter moisture content should be below 20 or 30 percent to keep ammonia levels in check. A scraper can be used to keep litter from getting too deep – and becoming an invitation for floor eggs. Consistent airflow in the house is essential to keeping litter dry.