Dietary orange frit on antioxidant capacity and hematological profile of Nile tilapia subjected to heat-induced stress

Author(s)

Igor Simões Tiagua Vicente

• Document type: Master's Dissertation
• Press: Botucatu. 2017-06-07.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Medicina Veterinária e Zootecnia. Botucatu
• Defense date: 2017-05-19
• Advisor: Margarida Maria Barros; Luciana Francisco Fleuri

Abstract

The antioxidant capacity of dietary orange frit (OF) on growth, hematological profile and antioxidant enzymes activity of Nile tilapia subjected to heat-induced stress (HIS) was analyzed. A group of 440 male Nile tilapia (31.7g ± 0.34) was randomly distributed in 40 250-L aquaria (11 fish/tank) and fed five practical diets with graded levels of OF at 0, 0.2, 0.4, 0.6 and 0.8% OF orange frit kg-1 diet for 70 days. The diets were formulated to contain 26% digestible protein and 14.24 MJ digestible energy kg-1. After the feeding period, growth performance, hematological profile and antioxidant enzymes activity were determined. Then, fish were subjected to HIS (32°C) for three days and the same hematological profile and antioxidant enzymes activity were determined. There was no statistical difference for growth performance among treatments. Fish fed 0 OF diet showed lower hematological profile after HIS (P < 0.05). Fish fed 0.6OF presented lower hematocrit and fed 0.8 OF lower hemoglobin and hematocrit after HIS. Fish fed 0.4 OF showed the lowest mean corpuscular volume (MCV) and the highest mean corpuscular hemoglobin concentration (MCHC) comparing the vales before and after HIS. Dietary orange frit determined different activities (P < 0.05) for catalase before HIS. Fish fed 0 OF diet showed the highest activity and 0.2 OF the lowest. After HIS fish fed 0 OF and 0.2 OF showed the lowest activity and 0.6 OF the highest (P < 0.05). A comparison of the values before and after HIS showed the highest values after stress. The highest activity for glutathione peroxidase, before HIS, was observed for fish fed 0 OF and the lowest for 0.2 and 0.4 OF (P < 0.05). After HIS the highest activity was determined for fish fed 0.6 OF and the lowest for fish fed 0.8 OF (P < 0.05). Dietary OF determined the highest enzymes activity when comparing values before and after stress. In sum, based on hematological profile and some antioxidant enzymes activities the dietary supplementation of 0.8 % of orange frit contributed to Nile tilapia maintain erythropoiesis and antioxidant capacity under heat-induced stress. (AU)

• FAPESP's process: 15/18072-3 - Use the orange frit in diets for Nile tilapia: growth performance and antioxidant system
• Grantee: Igor Simões Tiagua Vicente
• Support Opportunities: Scholarships in Brazil - Master