Amino acids digestibilities of protein supplements using caecectomized roosters

The apparent and true amino acid digestibility of rapeseed meal and undecorticated sunflower meal was determined in caecectomized cockerels. Adult White Leghorn cockerels (36) were divided into two equal groups, one group of birds was caecectomized. Each test ingredient was offered to six caecectomized and six intact cockerels individually. The apparent digestibilities of lysine, arginine, histidine, methionine and phenylalanine of sunflower meal and most of the amino acids of rapeseed meal were higher (P<0.01) in intact cockerels. The true digestibility of most of the amino acids of rapeseed and sunflower meals was higher (P<0.01 to 0.001) in intact cockerels. The intact cockerels tended to overestimate the amino acid digestibility of rapeseed and sunflower meals. The results suggested that the amino acid digestibility values of rapeseed meal and sunflower meal determined using caecectomized cockerels might be appropriate and reliable for application in poultry diet formulations.