Global Journal of Fisheries Science

This study evaluated the effects of the fermented and cooked blood meal-bovine rumen digesta diets fed to the fish juveniles on the histopathology and haematological properties of Clarias gariepinus juveniles. Five iso-nitogenous experimental diets containing 40% CP were formulated based on the proximate composition of used feedstuffs. Two sets of the experimental diets were formulated using fish meal, cooked blood meal-bovine rumen digesta (CBMBRD), fermented blood meal- bovine rumen digesta (FBMBRD), yellow maize, wheat offal, vegetable oil, mineral and vitamin premix. The experimental diets were formulated to replace fish meals with either cooked or fermented bovine rumen digesta blend at 25 and 50% inclusion levels respectively. A formulated diet without BMBRD meal inclusion served as a negative control diet while the commercial feed served as a positive control diet. One hundred and eighty (180) apparently healthy fish with the same nutritional history were selected, weighed and randomly distributed into each of the 18 labelled fish tanks (0.5 m³) at the rate of 10 fish per tank. At the end of the 24 weeks feeding trial, three fish were randomly selected from each tank for haematological and histopathology assessment using standard methods. Blood samples which were taken from the fish using caudal puncture were kept in heparinized tubes for various haematological determinations. Significantly higher (p˂0.05) packed cell volume (PCV) was obtained in the fish fed 50% CBMBRD while higher red blood cell count (RBC) was recorded in the fish fed the 0% BMBRD. The fish fed 25% CBMBRD diet had the lowest WBC count (50.83±3.11) which was significantly lower (p˂0.05) than in the fish fed other experimental diets. The liver and kidney of the experimental fish were carefully dissected out, preserved in 10% formalin and processed for histological analysis using appropriate histological techniques. Apart from the liver of the fish fed the commercial control diet where several fatty lobular spaces were recorded, the liver of the fish fed the experimental diets had a normal architectural arrangement of cells. The kidneys of the fish fed the commercial diet and 50% CBMBRD diets had vascular congestion and edema, however, the fish fed other experimental diets had no recorded abnormalities. The study therefore concluded that cooked and fermented blood meal–rumen bovine digesta meals had no obvious adverse effect on the histology and haematology profiles of C. gariepinus.