tested which contained 0, 130, 260 and 390 g kg 1, respectively, of oven-dried CoP. The
diets were formulated to be approximately isonitrogenous (Table 2). All dry ingredients
were mixed during 15 min before adding the lipids. Subsequently, mixing continued for
another 15 min. Next, water was added gradually until a desirable paste-like consistency
was reached. This paste was forced through a 1-mm die using a meat grinder. Pellets were
then dried for 16 h at 50 jC. Finally, the feed was manually crumbled to pellet size. Feeds
used in the aquaria study were supplemented with 1 g kg 1 Cr2O3 for determination of
apparent digestibility coefficients (ADC).