Nutritional Strategies To

Introduction The development of a sustainable, profitable, and competitive egg-production system is becoming a challenging issue facing the laying-hen industry. The excretion and volatilization of nitrogen and the emission of volatile organic compounds of dietary origin are responsible for a large part of the environmental issues that have risen from the intensive poultry production. Especially for layer houses, ammonia is recognized as a major aerial pollutant and may adversely affect rural residential property values and the public’s attitude towards intensive egg-production systems (Mackie et al., 1998; Herriges et al., 2003). Moreover, high levels of air-borne ammonia in poultry houses adversely affects egg production, worker health, and the public perception of the egg-production industry (Deaton et al., 1982; Morse, 1995; Mackie et al., 1998; Moore, 1998; Yang et al., 2000; Whyte, 2002). Especially during winter, the ammonia concentrations in many high-rise houses will exceed the levels recommended in industry guidelines (Liang et al., 2003; United Egg Producers, 2005). Moreover, Federal regulations (i.e., CERCLA and EPCRA) permit a maximum of 100 lb of ammonia be emitted per day. Thus, strategies to lower ammonia emissions from layer houses and manure-storage barns (containing manure from manure-belt houses) need to be identified and evaluated.