Effects of dietary olive oil and butyl hydroxytoluene (BHT) on digestive and hepatic enzymes, liver and intestinal histology in young Persian sturgeon, Acipenser persicus in brackish water

Document Type : Research Paper


1 Fisheries Department, Lahijan Branch, Islamic Azad University, Lahijan,, Iran

2 International Sturgeon Research Institute of the Caspian Sea, Agricultural Research, Education and Extension Organization (AREEO), Rasht,, Iran


This study was carried out to determine the effects of olive oil and dietary butyl hydroxytoluene on digestive and hepatic enzymes along with histology of liver and intestine in Persian sturgeon, Acipenser persicus. 315 pieces of young Persian sturgeon (108 ± 0.02 g in weight) were randomly stocked in 7 treatments with 3 replicates (15 fish in each replicate) after adaptation to the Caspian Sea water. The treatments were fed with 1% (T1), 3% (T2) and 5% (T3) olive oil and 100 (T4), 150 (T5) and 200 mg/kg (T6) butyl hydroxytoluene as well as one control group without any additive. At the end of the period, the levels of digestive and liver enzymes were measured, followed by the liver and intestine histological examinations. The results showed the highest levels of alkaline phosphatase and aminotransferase in T1 and alanine aminotransferase in T2 (p<0.05). The highest levels of catalase were also observed in T3, glutathione peroxidase in T4 and superoxide dismutase in T3 (p<0.05). The liver and intestinal tissues fed with olive oil were normal. However, in the liver and intestinal tissues of fish fed with butyl hydroxytoluene, bleeding and hyperemia, biliary leakage, cell atrophy, degeneration, tissue necrosis and cell swelling were observed. According to the results, adding butyl hydroxytoluene as a synthetic antioxidant to the diet of young Persian sturgeon is not recommended and it is better to replace it with olive oil.