Evaluation of kikuyu grass and moringa leaves as protein sources in Oreochromis mossambicus diets

Abstract

The ability to utilise leaf meal-based diets by Oreochromis mossambicus of 12.5 g (SD 1) was evaluated. Nine diets of 30% crude protein and 20 MJ gross energy kg^–1 dry matter were formulated, comprising eight leaf-meal diets, where kikuyu leaf meal (KLM) and moringa leaf meal (MLM) each replaced 25%, 50%, 75% and 100% fishmeal, and a control diet containing no leaf meal. The experiment was conducted for 60 days in a recirculating system. All diets were randomly assigned to three groups of 15 fish. There was a significant decrease (p < 0.05) in growth with increasing levels of both leaf meals. Superior growth, higher protein digestibility and higher feed utilisation were recorded in fish fed KLM diets than those fed MLM diets. Fish fed MLM had higher numbers of goblet cells in the enterocytes, higher hepatocyte degradation and poorer haematological parameters than those fed KLM diets. Kikuyu grass has lower levels of anti-nutrients such as tannins, saponins and phytate than moringa leaves. The negative effects of anti-nutrients may be responsible for the poor performance of fish fed the moringa-based diets. Kikuyu leaf meal can replace up to 25% fishmeal in O. mossambicus diets.