Feed additives are known for their economic importance in aquaculture. However, the aftermath of using synthetic additives on fish could lead to antibiotics resistance, altered behavior and reproductive issues in aquaculture species. Therefore, extract of Atama Heinsia crinita leaves with known medicinal value, was used in the diet of Nile tilapia Oreochromis niloticus as substitute to assess its relevance on the growth and haemato–biochemical, as gut bactericide, and its economic feed conversion ratio.
Nile tilapia (4.0±0.63 wt., n = 180) were conditioned and fed 35% crude protein isonitrogenous diets with graded levels of Atama leaves extract at 0.0g, 2.0g, 4.0g and 6.0g per 1000g DM for 8 weeks. The growth, haemato–biochemical and gut bactericidal effect, and the economic feed conversion ratio (EFCR) of production were assessed using standard weighing, analytical and microbiology procedures, and also profit equations respectively.
The weight gain (g) of Nile tilapia fed diet–based Atama leaves extract was significantly (p ˂ 0.05) improved from 2.0–6.0g/1000g DM diet inclusion by 34%. The FCR was significantly reduced, while the SGR (%/g/day) increased with the addition of dietary Atama leaves extract. The haemato–biochemical changes indicated significant improvement from the controlled diet. There was significant decrease in monocytes, eosinophils and basophils from 0.0g–6.0g/1000g DM. Similarly, aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) and creatinine declined. The gut bacterial isolates
(106 CFU/g) significantly declined with increased dietary inclusion of Atama leaves extract. In addition, the EFCR significantly reduced in the 6.0g/1000g DM diet by 23% from 0.0g/1000g DM diet. In conclusion, Atama leaves extract–based diets had substantial effect on the growth, physiology and distribution of gut bacteria in Nile tilapia.