PERFORMANCE OF BACILLUS SUBTILIS IN IMPROVING GROWTH, HAEMATOLOGICAL AND LIVER HEALTH OF THE AFRICAN CATFISH (Clarias gariepinus, BURCHELL 1822)

Abstract

The purpose of this research was to assess the effects of dietary probiotic (Bacillus subtilis) supplementation on haematology, growth and health of Clarias gariepinus. The feeding trial was conducted for 8 weeks. Average-weighted fish of 13.0 ± 0.22g were distributed into four groups, one of which was a control and the remaining three as treatment groups. The control diet (0 g/kg Bs) was made without the addition of probiotics, whereas the remaining three groups were prepared supplemented with the probiotic at different levels (10g/kg Bs, 20g/kg Bs and 30g/kg Bs). The length and weight of experimental fish were taken at intervals 0,15,30,45 and 60 days to evaluate growth parameters (initial weight, final weight, feed conversion ratio, weight gain) and body indices (condition factor, viscerosomatic index, and hepatosomatic index) of experimental fish. Blood samples were collected at the intervals 30 and 60 days for liver, plasma chemistry and haematological analysis. The haematological parameters such as red blood cells, haematocrit, haemoglobin concentration, and haematological indexes (mean corpuscular volume, mean corpuscular haemoglobin and mean corpuscular haemoglobin concentrations) were examined. Total protein and albumin levels were measured in the plasma and also examined. Aspartate aminotransferase, Alanine transaminase and Alkaline phosphate were analysed to check the state of the liver. After eight weeks, the results showed that, fish groups fed with treated diets showed much significant improvement in growth and condition indices in comparison to the control group. The Bacillus fed group (10g/kg Bs) showed an increase significantly in haematological parameters than in other groups. An increase significantly in Aspartate aminotransferase, Alanine transaminase and Alkaline phosphate were observed at the end of four weeks in the Bs treated diets in comparison to the control group, decreasing significantly at the end of eight weeks to optimum ranges compared to the control. The result suggests that dietary administration of Bacillus subtilis at 10g/kg can be used effectively to improve growth and health status of fish.