Cooked sesame meal in the diet of African catfish Clarias gariepinus (Burchell 1822): Effects on haematology, liver and kidney histology

Abstract

Haematological and histological alterations are strong pointers to the health status of farmed fish, farm animals and even humans. These provide dependable information on metabolic disorders and deficiency. The haematological and histological changes in African catfish Clarias gariepinus (Burchell 1822) fingerlings fed cooked sesame (Sesamum indicum) seed meal was examined in a 56-day feeding trial. Three batches of sesame seeds were cooked for 10, 20 or 30 min, dried, milled, and mechanically defatted using a screw press. Cooked seed meals (CSM) were substituted for defatted soybean meal in the diets of African catfish at 15, 30, and 45 per cent. The highest haemoglobin content (Hb) was found in catfish fed the control diet (CTR), while the lowest Hb levels were found in catfish fed the CSM345 diet. The haemoglobin content of catfish fed different dietary treatments varied significantly (P<0.05). Hb values of catfish fed CTR diet and test diets CSM115, CSM215, CSM315, and CSM130 were not significantly different (P>0.05). Other haematological parameters of the fish fed various dietary treatments showed a similar trend as RBC. Dietary replacement of soybean meal by differently cooked sesame seed meal in Clarias gariepinus diet did not affect haematology of the fish at lower inclusion levels for the different cooking times employed in the study (15% and 30% inclusion level for 10 min cooked sesame-based diets; 15% inclusion level for 20 and 30 min cooked sesame-based diets). Although, there was marked vacuolation of hepatocytes in catfish subjected to various dietary treatments, however these did not relate to dose-dependent dietary treatments.