Growth, Metabolic, Hepatic and Redox Parameters, Digestive Enzymes and Innate Immunity in Mugil liza Fed a Citral-Supplemented Diet

Mugil liza juveniles (6.69 ± 0.06 g) were subjected to dietary citral (0-control, 0.5, 1.0 and 2.0 mL per kg feed) for 45 days, and its possible effects on zootechnical and metabolic parameters, digestive enzymes, innate immunity, oxidative status and liver damage were evaluated. At the end of the experiment, fish fed 2.0 mL citral per kg feed showed a greater weight gain and protein retention efficiency, as well as enhanced activities of pepsin (stomach) and amylase (intestine) compared with control fish. Citral supplementation decreased liver lipoperoxidation and increased the activities of glutathione peroxidase, glutathione-S-transferase and superoxide dismutase in the gills, liver and brain. The highest level of citral inclusion augmented non-protein thiol content in the brain and gills. Myeloperoxidase activity was lower in fish offered 1.0 and 2.0 mL citral per kg feed. Dietary citral did not influence the plasma levels of aspartate aminotransferase and alanine aminotransferase or the hepatic histology. As it improved growth, the activity of digestive enzymes and general health, dietary citral may be recommended for M. liza at 2.0 mL per kg feed.