Animal feed and methods for reducing ammonia and phosphorus levels in manure

Abstract

An animal feed is provided that employs a substantially indigestible cation exchanger capable of binding ammonium cations and an acidogenic substance to acidify an animal's manure and thereby create ammonium cations that can be bound by the cation exchanger. The animal feed reduces ammonia emissions from manure produced by animals fed the animal feed compared to the emissions obtained from manure when an acidogenic substance is fed alone and compared to the emissions obtained from manure when a cation exchange capacity material is fed alone. According to another aspect of the present invention, a method of lowering ammonia emissions from manure is provided. The present invention also provides a method for reducing soluble phosphorus levels in manure and a method for reducing total phosphorus levels in manure. In a further aspect of the present invention, a method is provided that yields manure that may be used alone or in concert with other materials to act as a fertilizer having advantageous ecological properties. Another aspect of the present invention provides a method for reducing insect populations associated with manure.

Description

[0001] This application is a continuation of U.S. patent application Ser. No. 10 / 868,070 filed Jun. 15, 2004, which claims the benefit of U.S. patent application Ser. No. 60 / 499,988 filed on Sep. 4, 2003, U.S. patent application Ser. No. 60 / 541,500 filed on Feb. 3, 2004, and U.S. patent application Ser. No. 60 / 541,622 filed on Feb. 4, 2004, all of which are hereby incorporated by reference.FIELD OF THE INVENTION [0002] The invention relates generally to animal feeds and methods of feeding animals that produce more environmentally benign waste products. BACKGROUND [0003] The number one complaint filed with both state and federal environmental agencies against animal producers involves odors. What is true for animal producers in general is also true for poultry producers. Controlling odors associated with poultry manure is a continuing problem for poultry and egg producers. Aerosol ammonia is one of the primary causes of nuisance odors associated with confined animal feeding operation...

AI Technical Summary

Benefits of technology

"The patent describes an animal feed ration that reduces the level of ammonia in manure produced by animals fed the ration. This is achieved by using a cation exchanger that binds ammonium cations and an acidogenic compound that lowers the pH of the manure. The reduced ammonia levels help to reduce the level of aerosol ammonia, which can be a health hazard. The ration also helps to control the number of insects associated with the manure. The manure produced by animals fed this ration has a more favorable nitrogen to phosphorus ratio and is better for use as fertilizer."

Problems solved by technology

Controlling odors associated with poultry manure is a continuing problem for poultry and egg producers.

Aerosol ammonia is one of the primary causes of nuisance odors associated with confined animal feeding operations.

In addition to ammonia's role as a component in nuisance odors, high levels of gaseous ammonia adversely affects animal health and the safety of people working in these environments.

Gaseous ammonia levels are especially high in winter, when hen house ventilation is restricted to conserve heat.

In addition to ammonia's adverse effects on animal health, exposure to high levels of aerosol ammonia also adversely impacts human health.

For example, exposure to aerosol ammonia concentrations in the range of 25 parts per million (ppm) produces discomfort in workers, and even brief exposures (<5 minutes) to ammonia can cause nasal irritation and dryness.

OSHA also recognizes that an aerosol ammonia concentration of 300 ppm ammonia is immediately dangerous to life or health (IDLH).

In addition to the problems associated with aerosol ammonia in animal manure, manure often times comprises high concentrations of water-soluble forms of phosphorus.

High concentrations of phosphorus can cause environmental problems, especially if the phosphorus finds its way into surface water sources or shallow aquifers.

Manures from monogastric animals such as hogs and poultry are especially high in phosphorus due to the inability of monogastric animals to digest phytic acid, a phosphorus-rich compound commonly found in animal feeds.

The presence of high levels of soluble phosphates in manure is especially problematic when manure is disposed of by spreading it over fields or when feedlots are located near watersheds or above shallow aquifers.

While plants require phosphorus in order to grow, excess levels of phosphorus can stunt plant growth and in some cases cause plant death.

This is especially problematic, as one common means of disposing of manure is to use it to fertilize plants.

Especially if manure is already high in phosphorus, as ammonia is off-gassed the N:P ratio may become so low that the manure must undergo costly processing before it can be used as a fertilizer.

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