Determination of standardized prececal protein digestibility of canola meal in British United Turkeys Big 6 at different ages using multiple linear regression procedure

ABSTRACT Ninety six 2weekold British United Turkeys (BUT) Big 6 were assigned to 2 groups (4 replicates of 12 birds each). One basal diet and another one in which 20% canola meal replaced the corn starch in the basal diet were prepared. At 9, 16 and 21 wk of age, four birds from each pen slaughtered for digesta collection. The last twothird segment of the intestine, between the Meckel’s diverticulum and about 2 cm anterior to the ileocecacolonic junction, was excised. The diets and digesta were analyzed for dry matter, crude protein, and chromic oxide content. The standardized prececal protein digestibility of canola meal was calculated using multiple linear regression procedure. The standardized prececal protein digestibility of canola meal at 21 wk of age was significantly lower as compared with that of 9 wk of age; the relative weight of digestive organs also decreased significantly with increasing age (P lt; 0.05). By using multiple linear regression which accounted for the endogenous nitrogen losses, we showed that standardized prececal protein digestibility was also influenced by the age.