Manure

 ( Feces ) 

Animal manures may be adulterated or contaminated with other animal products, such as wool (shoddy and other hair), , blood, and bone. Livestock feed can be mixed with the manure due to spillage. For example, chickens are often fed meat and bone meal, an animal product, which can end up becoming mixed with chicken litter.

Other types of plant matter used as manure include the contents of the of slaughtered , spent grain (left over from brewing beer) and seaweed.

Odor is an obvious and major issue with animal manure. Components in swine manure include low molecular weight carboxylic acids, acetic acid, propionic acid, butyric acid, and . Other components include skatole and trimethyl amine.

Animal manures with a particularly unpleasant odor (such as slurries from intensive pig farming) are usually knifed (injected) directly into the soil to reduce release of the odor. Manure from pigs and cattle is usually spread on fields using a manure spreader. Due to the relatively lower level of proteins in vegetable matter, herbivore manure has a milder smell than the dung of or . However, herbivore slurry that has undergone anaerobic fermentation may develop more unpleasant odors, and this can be a problem in some agricultural regions. Poultry droppings are harmful to plants when fresh, but after a period of are valuable fertilizers.

Manure is also commercially composted and bagged and sold as a soil amendment.

In 2018, Austrian scientists offered a method of paper production from elephant and cow manure.

Dry animal dung is used as a fuel in many countries around the world.

In intensive agricultural land use, animal manure is often not used as targeted as mineral fertilizers, and thus, the nitrogen utilization efficiency is poor. Animal manure can become a problem in terms of excessive use in areas of intensive agriculture with high numbers of livestock and too little available farmland.

Manure can emit the greenhouse gas nitrous oxide, contributing to climate change.

may be much more or much less likely to contain antibiotics, depending on their sources and treatment of manure. For instance, by Soil Association Standard 4.7.38, most organic agronomy either have their own supply of manure (which would, therefore, not normally contain drug residues) or else rely on green manure crops for the extra fertility (if any nonorganic manure is used by organic farmers, then it usually has to be rotted or composted to degrade any residues of drugs and eliminate any pathogenic bacteria—Standard 4.7.38, Soil Association organic farming standards). On the other hand, as found in the University of Minnesota study, the non-usage of artificial fertilizers, and resulting exclusive use of manure as fertilizer, by organic farmers can result in significantly greater accumulations of antibiotics in organic foods.

• Album graecum
• Anaerobic digestion
• Barn cleaner
• Biosolids
• Chicken manure
• Coprophilous fungus
• Cow dung
• Dry dung fuel
• Earthen manure storage
• Liquid manure
• Manure spreader
• Reuse of human excreta

• Application and environmental risks of livestock manure
• North American Manure Expo
• Cornell Manure Program
• County-Level Estimates of Nitrogen and Phosphorus from Animal Manure for the Conterminous United States, 2002 United States Geological Survey
• Manure Management, Water Quality Information Center, U.S. Department of Agriculture
• Livestock and Poultry Environmental Learning Center, an eXtension community of practice about animal manure management
• Antibiotics and Hormones in Animal Manure (Webcast): A two part webcast series about the science available on potential risks and best management practices related to antibiotics and hormones from animal manure