Copaiba oil’s bactericidal activity and its effects on health and zootechnical performance for Nile tilapia after oral supplementation

Abstract

Abstract This study aimed to verify the bactericidal activity of Copaiba oil, Copaifera duckei, against the main tilapia pathogens and the effect on dietary levels of commercial Copaiba oil for 30 days on zootechnical performance, hematological, biochemical, immunological and histological parameters before and after an experimental infection with Streptococcus agalactiae in Nile tilapia. Fish were randomly distributed into 15 fiber tanks in five treatments (0%, 0.25%, 0.50%, 0.75% and 1.0%) and fed with commercial diet supplemented wit Copaiba oil for 30 days. After this period, the fish were randomly redistributed for the experimental challenge with S. agalactiae into six treatments (T0, T1, T2, T3, T4 and T5) and the fish were anesthetized, and blood samples were collected to assess hematological, biochemical, immunological and histological parameters. Copaiba oil showed bactericidal activity against Streptococcus spp. and Flavobacterium spp. in vitro. In addition, concentrations of 0.75% and 1.0% has an anti-inflammatory effect and improve hematological and immunological parameters, increasing the leukocyte numbers, albumin and serum lytic activity. Furthermore, there is an increase in the intestinal villus length and tissue damage in groups at concentrations 0.75% and 1.0% of Copaiba oil. In conclusion, oral supplementation enhanced non-specific immune parameters and digestibility in Nile Tilapia.