Physiology and Endocrinology: Stress and Inflammation: Effects on Animal Performance

The apparent digestibility coefficients (ADC) of unprocessed and processed pea, canola and flax products were determined on diets, in which 30% of a reference diet was replaced by each test ingredient. Celite was used as an indigestible marker for measuring apparent digestibility coefficients indirectly. The trial was conducted in a semi-closed recirculating system using 5 tanks per diet with 40 fish per tank, and feces were collected using a settling column. The processed ingredients included dehulled flax produced by abrasive dehulling, canola protein concentrate and pea protein concentrate, which were produced by aqueous extraction of peas and canola meal, respectively. Coextrudates of canola and peas (C:P) or flax and peas (F:P) were also tested. Processing had no significant effect on the ADC of crude protein except for flax. Whole flax had negative ADC for crude protein, energy and dry matter probably due to the high viscosity of this diet. Processing significantly improved the ADC of energy and dry matter for pea, canola meal and flax (P < 0.05). The ADC for crude protein for C:P was not significantly different than pea or canola meal while the ADC for crude protein for F:P was intermediate between flax and pea. The coextruded products had ADC for energy and dry matter that were significantly higher than those of the component ingredients (P < 0.05). The results suggest that these processing methods can significantly improve energy and dry matter ADC of pea, canola and flax by tilapia but have less effect on protein digestibility. Ingredient Crude protein Energy Dry Matter