Dietary Bougainvillea glabra leaf meal on growth, haemato-biochemical responses and disease resistance in Nile tilapia, Oreochromis niloticus against Enterococcus faecalis

Abstract

This study aimed to determine the effects of dietary supplementation of Bougainvillea glabra leaf meal on the growth performance, feed utilization, haemato-biochemical responses and disease resistance in juvenile Nile tilapia, Oreochromis niloticus. Five iso‑nitrogenous and isoenergetic diets were formulated with graded levels of B. glabra leaf meal, 0.0% (C), 1.5% (T1), 3.0% (T2), 4.5% (T3) and 6.0% (T4). The diets were randomly allotted to triplicate groups of 15 fish (1.5 ± 0.1 g) per experimental unit and fed until apparent satiation for 30 days. At the end of the feeding trial, growth performances, feed utilization and disease resistance were observed to be significantly higher in the fishes fed with B. glabra supplemented diet compared to the fishes fed with the control diet without B. glabra supplementation. Significant increase in growth performances, feed utilization were observed in fishes fed with 4.5% (T3) B. glabra supplemented diet. Haemato-biochemical parameters were not significantly (P > 0.05) affected by dietary supplementation of B. glabra at different concentration. After 14 days challenge test with Enterococcus faecalis (SRLFDA/TIL-1/15) at a concentration of 2 × 108 colony-forming units (CFU/mL) and the cumulative survival rates of fish fed with 4.5% B. glabra supplemented diet (T3) were significantly higher compared to other treatment and control groups. The present investigation suggests that B. glabra could be used as a feed additive to improve the growth performances and disease resistance in Nile tilapia. This forms the first report on the use of B. glabra leaf meal as the potential feed additive.