Properly managed, your compost heap should be able to attain composting temperatures of 110 to 160 degrees F, according to the USDA's Natural Resources Conservation Service. Nitrogen materials in your compost encourage heat generation, because they provide protein for the decomposing bacteria in the compost. As the bacteria use the protein to grow and reproduce, they let off heat. Avoid encouraging temperatures in excess of 170 degrees F to keep from destroying helpful bacteria in your compost.
If you're looking for a source of quick heat in your compost pile, acquire some protein meal. Supplemental protein powder gives the decomposing materials a quick shot of nitrogen, which may be just what you need to get your compost smoking---literally. Typically available for sale at your local garden supply store, common protein meal sources include alfalfa meal, blood meal, bone meal and cottonseed meal.
Protein meal is potent, so use it sparingly. Sprinkle no more than one or two layers 1/4-inch thick on your compost to provide a prompt heat generator. Supplement your protein meal generously with another slower-acting source of nitrogen, such as grass clippings, or else your hot compost pile will cool down once the bacteria consume the protein meal.
Animal feeds provide a heat-generating compost material for composters who want an inexpensive way to heat up their compost piles. According to Barbara Pleasant, co-author of "The Complete Compost Gardening Guide," you need to look no farther than your dog's food bowl for this prime source of heat for your compost pile. Good sources typically include bagged dog food, rabbit feed and goat feed, which all contain a high percentage of protein in various forms.
Not only is animal feed inexpensive, but if you already own a dog or some livestock, you may not even have to leave your property to find this cheap compost material. Avoid commercially bagged pig feed, which typically contains animal by-products, such as fats. Generally, about 20 lbs. of animal feed sprinkled in thin layers should be enough to jump start the heating process in your compost pile. Like protein meal, animal feeds require supplemental nitrogen sources, such as grass clippings, to help you maintain hot composting temperatures.
Opt for livestock manure if you're looking for a basic, foolproof, heat-generating compost material. An all-in-one compost ingredient, livestock manure works as an organic activator to get your compost heating quickly. It also provides the compost bacteria with a long-term source of nitrogen, so you don't have to supplement it with other nitrogen-rich ingredients.
The stand-by for farmers, ranchers and old-school composters, animal manure is available in large quantities wherever livestock congregate. You can often acquire it for free, as long as you're willing to put in time and labor to transport it yourself. Generally, livestock manure should account for no more than about 1/4 to 1/3 of your compost pile's volume; the rest of the pile should consist of carbon-rich materials, such as dead leaves, to promote oxygen flow and give the bacteria a ready source of energy. Never use manure from meat-eating animals, such as pigs or pets, since they contain potentially dangerous pathogens that can survive hot composting temperatures.