Effects of Curcuma longa on Growth and Biochemical Variables of Oreochromis niloticus Challenged with a Consortium of Bacteria

Abstract

This study evaluated effects of turmeric on growth and immune response of Nile tilapia. Five phytogenic feeds were formulated with varying inclusion levels of turmeric thus: F1 20 %/kg; F2 15 %/kg; F3 10 %/kg; F4 % g/kg and F5 0 %/kg. There was a commercial feed (F6) which served as the control experiment. Fish fingerlings (initial weight ca. 14.2g) were fed experimental diets for 70 days, thereafter, they were subjected to dual bacterial challenge by injecting a consortium of Staphylococcus aureus, Pseudomonas aeruginosa and Flavobacterium columnare into the culture media and then intraperitoneal injection of the bacteria into the fish muscle. Growth, nutritional performances and immunity of the fish were analyzed using standard procedure. Results showed that the relative protection levels of fish fed diets F1 to F3 were 100%, while 95.56% was obtained in group fed diet F4. A 0% mortality was recorded for fish fed diets F1 to F3, 4.4 % for those fed diet F4 and 100% for those fed diets F5 and F6. The best specific growth rate was recorded in fish fed diet F1 with the values decreasing with decrease inclusion levels of turmeric in diets. Alanine aminotransferase and aspartate aminotransferase reduced with the inclusion of turmeric. Results showed that increasing turmeric inclusion up to 20% in tilapia diet would increase growth rate and enhance immunity against bacterial diseases. Keywords: Turmeric, phytogenic feed, O. niloticus, bacterial challenge, aquatic microbes