Mitigating Ammonia Emissions from High-rise Hen Houses through Dietary Manipulation

Dietary manipulation can substantially lower ammonia (NH3) emissions from laying-hen houses or manure storage. Recent lab studies showed a NH3 emission reduction for experimental diets with EcoCal™ and corn dried distiller’s grain with solubles (DDGS) as compared to the standard or control diet. The study reported here was a field verification test about the effects of diets containing DDGS and EcoCal™ on air emissions, hen production performance, and the economic returns for a commercial high-rise layer operation in Iowa. Comparative data were collected during December 2007 to Dec 2009. Feeding EcoCal diet at 7% inclusion rate and DDGS diet at 10% inclusion rate to laying hens in the high-rise houses showed 39% and 14% overall reduction in NH3 emissions, respectively. There were few differences in egg production, egg weight or egg mass (output) for hens fed the EcoCal or DDGS diet as compared to hens fed the control diet. Compared with the control and DDGS hens, the EcoCal hens consumed more feed and had a lower mortality rate, and had a similar feed conversion. The EcoCal hens also tended to have a greater body weight. Egg production was slightly lower for hens fed the DDGS diet (424 eggs hen-1 or 58.5 lb hen-1) than that of the Control (435 eggs hen-1 or 59.2 lb hen-1M) and EcoCal (447 eggs hen-1 or 61.9 lb hen-1) hens. The lower egg production by the DDGS hens (during the first cycle) could have resulted from learning management of the new strain birds during the first cycle. The cash returns (revenue – total cost) of each hen were, respectively, $11.88, $11.18 and $12.35 for Control, DDGS and EcoCal regimens over the 91-wk production period.