Feather meal

Feather meal, also called feather powder, is a useful product made from poultry feathers. It is created by grinding feathers under heat and pressure, then drying them. Even though it contains a lot of nitrogen, the body can sometimes have trouble using it unless it is treated in a special way first, called hydrolyzed.

Feather meal is commonly used to make special animal feed and organic fertilizer. It helps turn something that used to be thrown away into something valuable.

Each year, around 50 billion chickens are used for food around the world. Their feathers were once seen as waste, but now using feather meal helps save energy and cut down on carbon emissions from throwing feathers away. This makes it an important and eco-friendly resource.

Animal feed

When feather meal is used to feed animals, the tough material in feathers needs to be broken down so animals can use it. One way to do this is called rendering, where steam and high pressure cook the feathers at temperatures above 140 °C (284 °F). After this, the feathers are dried, cooled, and ground into a powder. This powder can then be used as a protein source in animal feed, especially for animals like cows and fish.

There are other methods to break down the feathers, such as using acids, fermentation, or special enzymes.

Plant fertilizer

Feather meal contains a lot of nitrogen (15%) and sulfur (2.4%). It also has helpful plant nutrients like iron and zinc.^{: Table 3}  Since it is not made from chemicals or oil, it is an organic fertilizer.

Feather meal releases nitrogen slowly as soil microbes break it down. It does not dissolve in water, so it is best mixed into the soil. This helps plants grow green leaves and improves the soil by encouraging helpful microbes and helping with composting. There is also a type that releases nitrogen quickly.

Issues

Some countries used to add special medicines, like roxarsone, to chicken feed. Studies showed that using feather meal might lead to humans being exposed to a substance called arsenic exposure. The United States stopped allowing this medicine in 2013. More recent studies in China found higher levels of arsenic in soil near chicken farms, but these levels were still considered safe for people.

Chickens sometimes receive antibiotics and other medicines, and these can end up in their feathers. Some of these medicines do not disappear completely when the feathers are processed. The leftover medicines can affect certain bacteria, stopping them from growing, but they do not affect bacteria that are already resistant.