Effect of Moringa oleifera on the histology, haematology and growth of Oreochromis mossambicus in aquadams^® fertilised with chicken manure in South Africa

Abstract

The effect of Moringa oleifera seed powder on water quality and the histology, haematology and growth of Oreochromis mossambicus was investigated. Five dosage levels, 0, 100, 200, 300 and 400 mg l^–1, of M. oleifera seed powder were applied to aquadams^® (high-density polyethylene plastic fishponds) fertilised with chicken manure in a completely randomised design and replicated twice. Bicarbonate alkalinity and potassium increased with increasing M. oleifera dosages, whilst turbidity decreased. Dissolved oxygen was significantly higher in all M. oleifera treatments than in the control. Hepatic cord disarray, nuclei pleomorphism and cellular swelling were evident in the liver as the M. oleifera dosage increased. The testis histology showed degenerating sperm cells and atrophied seminiferous tubules in the 300 and 400 mg l^–1 treatments. The degree of histological alterations of the gills increased at dosages of 300 and 400 mg l^–1. There were significant differences in the white and red blood cell counts, haemoglobin and haematocrit, and in the mean corpuscular concentration, haemoglobin and volume, between the different treatments. Fish growth decreased with increasing dosage. The histological and haematological parameters indicated that fish health was compromised at the highest dosage, leading to slow fish growth at the higher dosages.