The two principal classes of odorous compounds are those containing sulfur, e.g., hydrogen sulfide, and those containing nitrogen in the amine form, e.g., ammonia. The generation of these compounds is affected by the type of livestock and is primarily associated with the level of protein and amount of roughage in feed ration. For example, poultry and hog wastes produce more offensive odors than cattle. The manure-handling system also affects the rate of odor generation and the characteristic smell of the odor. Manure that is collected and field-spread daily has less offensive odors than stored manure.
Research indicates that the transport of odors is also associated with dust particles or aerosols.
Therefore, controlling dust or aerosol emissions will help control odors. Good management is crucial to controlling odors. This includes both the proper operation of the manure-handling system and the neatness and cleanliness of the total facility. Good public relations with neighbors is essential. The farm operator must consider how a particular practice, e.g., agitating manure storage or spreading manure on a field, will affect the odor level being carried to a neighbor.