Feather meal

Feather meal, also called feather powder, is a byproduct of poultry processing made from ground poultry feathers. It is high in nitrogen, up to about 12 percent, though how much of that nitrogen an animal can actually use depends on processing. Feathers destined for animal feed are broken down through hydrolysis, commonly by rendering in steam pressure cookers above 140 degrees Celsius to cook and sterilize them before grinding into powder, with acid treatment, fermentation and enzyme processing used as alternative methods. Once the largely indigestible keratin is broken down, feather meal serves as a protein source in feed for ruminants and fish, and it is also used as an organic fertilizer, supplying around 15 percent nitrogen and 2.4 percent sulfur along with micronutrients such as iron and zinc; the native form releases nitrogen slowly as it decomposes in soil, while hydrolyzed feather meal releases it faster.