A note on the digestibilities of nitrogen and amino acids in meat, skimmed-milk and fish meals in young pigs

Abstract

In order to compare the digestibilities of amino acids in meat, skimmed-milk and fish meals, isonitrogenous, semi-purified diets containing these foodstuffs were given to five castrated male pigs, of 13 kg live weight, with ileo-rectal anastomoses. Apparent digestibilities were calculated as (amino acid consumption —Heal digesta amino acids)Iamino acid consumption. In the order, meat, milk and fish meal, digestibilities were: of N, 0·80, 0·84, 0·88 (s.e.d. 0·021); of lysine, 0·84, 0·94, 0·94 (s.e.d. 0·011); of threonine, 0·81, 0·86, 0·91 (s.e.d. 0·017); of methionine, 0-86, 0·94, 0·94 (s.e.d. 0·006). In vitro solubility of N in 0·2 gll solution of pepsin and hydrochloric acid was 0·93 (s.e. 0·003) for meat, 0·97 (s.e. 0·001) for milk, and 0·95 (s.e. 0·001) for fish meal. In conclusion, the digestibilities of essential amino acids were greater in the milk and fish meals, than in the meat meal.