Abstract 211

Green,-S; Bertrand,-SL; Duron,-MJC; Maillard,-R

A.E.C. Nutrition Labs., 03600 Commentry, Allier, France.

British-Poultry-Science. 1987, 28: 4, 643-652; 28 ref.

Three isonitrogenous diets were formulated in which soyabean (dehulled), sunflower (hulled) and groundnut (dehulled) meals were the only protein sources. Each of 24 intact and 24 caecectomized cockerels which had been previously starved for 48 h was given by tube 50 g of each diet. Excreta were collected, individually, for 48 h. The concentrations of amino acids in the diets and excreta were estimated, and digestibility coefficients calculated. Differences between intact and caecectomized cockerels for true digestibility evaluations reached significance for threonine, glycine and lysine only. Deamination of threonine and glycine, and synthesis of lysine, in the caeca was implied. Neither the true digestibility of nitrogen, nor that of the sum of the amino acids differed between protein sources. True digestibilities of most essential amino acids, considered individually, in sunflower and groundnut meals were similar to or greater than, those of soyabean meal. Exceptionally, lysine was more digestible in soyabean (0.879) than in sunflower (0.722) or groundnut (0.788) meals.