Rendering is a process that converts waste animal tissues into value-added materials.
Whole blood meal is produced by spray drying at low temperatures the fresh whole blood from animal processing plants. The fresh blood is typically collected in on-site cooling tanks that utilize agitation to prevent coagulation of the fresh blood. The whole blood is then centrifuged to remove foreign material. Whole blood meal contains about 80% crude protein, with 1% methionine (2.4% methionine + cystine).
Hydrolyzed poultry feathers or feather meal is produced by hydrolyzing clean, undecomposed feathers from slaughtered poultry. Hydrolysis is accomplished with steam and pressure which break the keratinous bond and increases the digestibility of the protein in the feathers. The quality of feather meal is affected by the length of time that it is hydrolyzed. The protein content of feather meal is typical 85%. If the content is 75% crude protein or less, the hydrolyzation was incomplete.
Fishmeal is a by-product of the fishing industry. It can be made from any type of fish, though in the United States menhaden is the most common. Fishmeal is an excellent, high-quality protein that can be used in poultry diets. Typically low levels are used to prevent off-flavors in the eggs or meat produced.
MEAT AND BONE MEAL
Meat meal is a by-product of the beef and pork slaughterhouse. We bones are included it becomes meat and bone meal.
POULTRY BY-PRODUCT MEAL
Poultry by-product meal is similar to meat and bone meal but is a by-product of the chicken and turkey meat industries rather than beef and pork.