水産養殖研究開発ジャーナル

概要

Phytogenic Feed Additive Supplemented Diets as Welfare Promoters under Acute and Chronic Stress Factors in Gilthead Seabream

Eleni Antoniadou, Ioannis T Karapanagiotidis, Panagiota Panagiotaki, Eleni Golomazou

Stress in aquaculture can be modulated by specific stress-limiting factors such as Phytogenic Feed Additives (PFAs), known for their welfare-promoting effects. Three stress trials with gilthead seabream were, therefore, conducted aiming at evaluating the possible beneficial role of three PFAs as welfare-promoters under stress-induced farming conditions, such as starvation (Trial I: Fish starvation for 14 days), high-density (Trial II: Fish were stocked in aquaria at 1.2 Kg/m³ and 2 Kg/m³) and intense handling procedures (Trial III: Fish were kept out of water in the open air for 5 min). Seven dietary treatments were supplemented with Cannabis sativa seed oil, Origanum vulgare, and Cinnamomum zeylanicum essential oils at 1% and 2%. DNA damage in hepatocytes and erythrocytes and blood cortisol were assessed as stress indices. Diets supplemented with PFAs proved to decrease induced genotoxicity under starvation in most cases and under high-density stocking conditions in the case of OR1% and CAN1% groups. However, their genoprotective role was not clear under intense netting procedures. Their positive impact was more obvious in cortisol values in all trials. Differences presented between the PFAs, the applied doses, and the examined tissues may be related to the toxic effects of PFAs and variations in DNA damage and repair mechanisms.