The composition of manure is very elusive. Farmers generally believe that manure has benefits as a fertilizer, but fall short of applying manure effectively. It is often difficult to know just what is in manure. Manure is highly variable from animal to animal and it changes moment to moment over time. Before getting into this discussion too deeply, the definition of manure needs to be further refined.
Manure is fresh fecal material.
It is a lot of unused food, so it has much the same chemical composition as the feed that animals consume. All animals produce manure, but the kinds of environmental problems that arise on most farms generate from manure products rather than manure itself. Manure products result from manure storage and treatment systems. Odors are manure products. Anaerobic lagoons digest and transform the manure into methane, nutrients, carbon dioxide and water.