2.2. In vivo ingredient digestibility determinations
2.2.1. Study design
Themethods of Cho et al. (1982) and Bureau et al. (1999) were used
with additional modifications described below to estimate ADCs of
GDDY in rainbow trout. A complete reference diet (Table 1) meeting
or exceeding all known nutritional requirements of rainbow trout
(National Research Council, NRC, 2011)with yttrium oxide as indigestible
marker was blended with the test ingredient (GDDY) in a 70:30 ratio
(dry-weight basis). Both the reference and test diet were manufactured
by cooking extrusion.