The non-mineral nutritional impact of phytate in canola meal fed to broiler chicks

Three experiments were conducted to study the effect of in vitro hydrolysis of phytate on the nutritional value of canola meal for broiler chickens. I n experiment 1 canola meal was incubated (1:2 meal:H2O; pH 5.0; 50 degreesC ) for 1.5 h with purified or crude phytase (Natuphos((R))), or without enzy me addition. Phytase addition hydrolysed 72-73% of meal phytate bur neither purified nor crude phytase improved broiler performance. Experiment 2 was designed to study the negative but non-significant effect of meal pre-treat ment on the performance of broiler chickens noted in experiment 1, Untreate d and four pre-treated meals were included in broiler diets. Pre-treatments consisted of water incubation (1:2 meal:H2O; pH 5.8; 50 degreesC; 1.5 h), acid incubation (pH 5.0), acid incubation followed by neutralisation with N aOH, and acid incubation followed by the use of additional dietary limeston e to balance the anionic contribution of the acid treatment. Dietary treatm ent did not significantly affect broiler performance. The objectives of exp eriment 3 were to study the effect of total phytate removal in canola meal on broiler performance. Treatments included canola meal and five pre-treate d meals: water incubation, acid incubation, acid incubation followed by neu tralisation with NaOH, and the latter treatment using either purified or cr ude phytase during incubation. Meals were mixed in a ratio of 1:2 (meal:H2O ) and incubated for 23 h at 50 degreesC. pre-treatment with acid followed b y neutralisation with NaOH reduced meal apparent metabolisable energy (AME( n)) and amino acid availability in comparison to the untreated control. Bot h purified and crude phytase improved AME(n) but only purified phytase impr oved amino acid availability. Broiler growth was unaffected by the eliminat ion of phytate. Phytase addition improved feed to gain ratio with the effec t of crude phytase being significant (P < 0.05). (C) 2001 Elsevier Science B,V. All rights reserved.