Fisheries and Aquaculture Journal
Open Access

Abstract

Mouldy Groundnut Cake and Hydrated Sodium Calcium Aluminosilicate in Practical Diet for African Catfish Clarias gariepinus (Burchell, 1822)

Comfort Adetutu Adeniji, Pius Abimbola Okiki, Ajani Murano Rasheed and Rasheed Bolaji

The study was designed to detect fungi and quantify aflatoxins B1 and B2 microbial load levels and toxin binding efficacy of hydrated sodium calcium aluminosilicate (HSCAS) on growth and nutrient utilization of Clarias gariepinus African catfish fingerlings diet formulated with mouldy groundnut cake (MGNC). MGC containing 185.00 ± 7.07 μg/kg and 137.50 ± 10.00 μg/kg of aflatoxins B1 and B2 was incorporated into practical diets. Three practical isoproteinous diets were formulated. Diet 1 contained Groundnut Cake (GNC) with 0.20 ± 0.14 cfu microbial load but no apparent mould contamination. Diet 2 contained MGC 4.38 ± 0.40, 1.99 ± 0.01 μg/kg of aflatoxins B1, B2 and 2.20 ± 0.14 cfu microbial load. Diet 3 contained MGC, HSCAS; 3.49 ± 0.20, 1.34 ± 0.01 μg/kg and 1.35 ± 0.20 cfu of aflatoxins B1, B2 and microbial load, respectively. The diets were fed twice daily to Clarias gariepinus fingerlings mean body weight 1.68 ± 0.01g in triplicate of 20 fish each for 12 weeks. Six fungi; Aspergillus parasiticus, A. flavus, A. niger, A. tamarii, Penicillium citriinum and P. oxalicum were isolated from MGNC diet. Addition of HSCAS reduced fungi present in diet 3 to A. flavus, A. tamarii and P. oxalicum. Also aflatoxins B1, B2 and microbial load in the diet and carcass of Clarias gariepinus were reduced with HSCAS inclusion in diet 3. Feeding African catfish fingerlings with mould contaminated diet (2) significantly (P<0.05) reduced growth performance and feed utilization but had no significant (P>0.05) effect on survival of Clarias gariepinus fingerlings. The results of this study show that the inclusion of HSCAS reduced the number of fungi, microbial load and aflatoxins B1 and B2 in the carcass and diet of African catfish formulated with mouldy GNC. But was not effective in alleviating the growth depression induced by mould contamination of the diet. Hence the need for identification of toxins present in mould contaminated feedstuffs in order to design effective toxins management strategies.