Experiment 4. A fourth experiment was conducted using custommade,
isonitrogenous, isocaloric diets to compare Vg production in
male tilapia fed a fish meal-based diet versus that in fish fed a soybean
meal-based diet. The ingredients and estimated nutrients of the
defined feeds are shown in Table 1. Fish were kept in separate tanks
and fed commercial trout diet, a custom-designed fish meal-based
diet, or a custom-designed fish meal-free diet (soy-based diet), containing
soybean meal as the primary protein source (10 fi
sh/
treatment). They were fed to apparent satiation once daily. Blood
was sampled after 20 days, as described above.