Apparent and True Digestibility of Amino Acids of Meat Cum Bone Meal and Fish Meal in Caecectomized Roosters

Abstract

The apparent and true amino acid digestibilities of silver fish meal and meat cum bone meal were determined using adult caecectomized roosters. Each test ingredient was offered to six caecectomized and six intact cockerels individually. The apparent digestibilities of indispensable amino acids of fish meal, with the exception of methionine and threonine were significantly higher in caecectomized than in intact birds. Whereas the apparent digestibilities of methionine, cystine, threonine, valine and serine of meat cum bone meal were higher in intact birds in comparison to their caecectomized counterparts. The true digestibilities of all the amino acids of fish meal were similar between caecectomized and intact birds. In contrary, except arginine and phenylalanine, all the essential amino acids of meat cum bone meal had higher digestibility in intact as compared to caecectomized cockerels. The intact cockerels underestimated the apparent amino acid digestibilities of fish meal, while overestimated that of meat cum bone meal. When true amino acid digestibility was taken into account, no significant difference was observed for fish meal between caecectomized and intact cockerels. On the other hand, the intact cockerels overestimated the digestibility of meat cum bone meal. These results suggested that the amino acid digestibility values of meat cum bone meal and fish meal determined using caecectomized cockerels might be appropriate and reliable for poultry diet formulations based on apparent digestible values. It also suggests that when the poultry diets are formulated on the basis of true digestibility values, the digestibility data of meat cum bone meal generated from caecectomized birds and that of fish meal generated either from caecectomized or intact cockerels can be effectively applied.

Keywords

• amino acid digestibility
• caecectomized cockerels
• fish meal
• meat cum bone meal