
Dietary supplementation of dry oregano leaves increases the innate immunity and resistance of Nile tilapia against Streptococcus agalactiae infection
2019; Wiley; Volume: 51; Issue: 2 Linguagem: Inglês
10.1111/jwas.12602
ISSN1749-7345
AutoresAmanda Hastenreiter Espirito Santo, Túlio Soares de Brito, Laura Lanna Brandao, Guilherme Campos Tavares, Márcia Pimenta Leibowitz, S. A. Prado, Vany Ferraz, Daniela Chemim de Melo Hoyos, Eduardo Maldonado Turra, Edgar de Alencar Teixeira, Henrique César Pereira Figueiredo, Carlos Augusto Gomes Leal, Paula Adriane Pérez Ribeiro,
Tópico(s)Fish Biology and Ecology Studies
ResumoThis study aimed to evaluate the influence of increasing concentrations of dietary dry oregano leaves (DOL), ranging from 0 to 0.15%, on different performance parameters of Nile tilapia. Hence, two separate experimental trials testing growth factors (Trial 1) and innate immunity and disease resistance against Streptococcus agalactiae infection (Trial 2) were conducted with a total of 464 tilapia juveniles and two to four replicates. As a result, dietary inclusion of DOL did not induce significant effects on growth performance, hematological parameters, and fillet composition. However, there were significant differences in lysozyme activity between groups of DOL at 0.075% and the control (0%). Moreover, the bactericidal index of the positive control and groups supplemented with DOL were significantly higher than baseline treatment groups. For disease resistance, there was a reduction of 15% in the relative risk of streptococcosis in fish juveniles after dietary inclusion of oregano at 0.15%. In conclusion, the inclusion of DOL in tilapia diets resulted in no significant gains in terms of growth; nevertheless, the immune system and resistance of tilapia against S. agalactiae infection were significantly improved.
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