A 60-day feeding trial was conducted to evaluate the effects of formic acid (Amasil®
NA), β-carotene (Lucarotin® 10% Feed) and vitamin E (Lutavit® E 50 S) on growth,
survival, prevention of Vibrio infection and immune parameters of Pacific white shrimp.
In Experiment 1, postlarvae-12 were randomly distributed into six groups and then fed four
times daily with the following diets as treatments: 0.3% formic acid, 50 ppm β-carotene,
50 ppm β-carotene + 0.3% formic acid, 400 ppm vitamin E and no feed additives (positive
and negative control groups).