Beta-glucan and its eight derivatives were added to the basal
diet at two doses: 0.1% and 0.2%, respectively, to prepare 18 experimental
diets. The basal dietwas used as a control. All the dietary ingredients
were ground into a fine powder through a 149 μm mesh sieve, and
mixed thoroughly with fish oil and cold water. Then the mixture was
passed through an extruder with a 1.5 mm die to produce ‘spaghettilike’
strings. After drying, the diets were cut into the appropriate pellet
and stored at −20 °C.