Animal protein sources such as fish meal and protein plasma are often used in diets fed to weanling pigs because the amino acids in these sources are highly digestible and because animal protein sources do not contain the anti-nutritional factors present in soybean meal. However, the cost of fish meal has increased in recent years and there is, therefore, a need for less expensive alternatives.

Chicken meal and and poultry by-product meal are protein ingredients that have a concentration of amino acids similar to that of fish meal. Poultry by-product meal is produced from the offal of carcasses of slaughtered poultry and includes feet, necks, undeveloped eggs, and intestines. Chicken meal is prepared from clean flesh and skin of chickens without or with bone derived from the whole carcass of poultry. The quality of chicken meal and poultry by-product meal depends on the quality of the rendered parts to produce them. Ultrapro is produced from enzymatically hydrolyzed porcine intestines, and AV-E Digest is produced by enzymatically hydrolyzing whole spent hens and extruded egg albumins. Insufficient data exist on the digestibility of crude protein and amino acids in these ingredients.  Therefore, an experiment was conducted to determine the digestibility of crude protein and amino acids in chicken meal, poultry by-product meal, Ultrapro, and AV-E Digest when fed to weanling pigs and to compare these values with values obtained for soybean meal.