IJAMBR 3 (2015) 20-30 ISSN 2053-1818 Enhancement of the nutritive value of cocoa (Theobroma cacao) bean shells for use as feed for animals through a two-stage solid state fermentation with Pleurotus ostreatus and Aspergillus niger Bentil, J. A. 1 *, Dzogbefia, V. P. 2 and Alemawor, F. 2 1 Department of Animal Science, College of Agriculture and Natural Resources, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana. 2 Department of Biochemistry and Biotechnology, College of Science, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana. Article History ABSTRACT Received 10 December, 2014 Received in revised form 07 January, 2015 Accepted 14 January, 2015 Key words: Agroindustrial by- products, Cocoa bean shells, Solid state fermentation, Aspergillus niger, Pleurotus ostreatus, Theobromine. Article Type: Full Length Research Article The study investigated the suitability of cocoa bean shell (CBS), a by-product from cocoa processing industry as alternative energy source for animal feeding when subjected to a two-stage solid state fermentation with Pleurotus ostreatus and Aspergillus niger. It involved the optimization of the fermentation period by the afore-mentioned fungi. The already dried shells were milled into 2 mm particle size, composted and pasteurized. The pasteurized substrate was fermented with the spawn of P. ostreatus (oyster mushroom) for six weeks followed by A. niger fermentation for seven days. The fermentation of the shells with P. ostreatus significantly increased (p<0.05) the protein content by 25.22% and decreased (p<0.05) the cellulose, hemicellulose and lignin by 49.93, 39.99 and 34.65% respectively, at the sixth week; the optimum fermentation period. The degradation of the complex carbohydrates by the fungus increased the level of soluble carbohydrates from 35.05 to 45.30% which resulted in a 33.64% increase in metabolizable energy (M.E) in the fermented product. The calcium, phosphorus and potassium contents of the P. ostreatus fermented shells were also significantly enhanced (p<0.05) at the end of the fermentation period. The P. ostreatus fermented CBS which was subsequently fermented with A. niger had its theobromine content significantly reduced (p<0.05) by 72.89% at the end of the seven days of fermentation. The CBS fermented product hence becomes more suitable for use as animal feed material. ©2015 BluePen Journals Ltd. All rights reserved INTRODUCTION The poultry industry is faced with several challenges one of which is the scarcity of conventional energy source feedstuffs particularly maize, a major energy source in animal feed. This is due to the high demand on such ingredients by humans and in the poultry and livestock *Corresponding author. E-mail: profdocjab@yahoo.com. industries. The high competition for energy source ingredients between humans and animals has led to escalating prices of these ingredients hence increased the cost of feeding (Adebowale, 1981). Several attempts have been made by researchers to address this pestering issue facing the poultry industry by the use of alternative and cheaper sources of ingredients to replace the less available and expensive ones (Olubamiwa et al., 2000; Hamzat and Babatunde, 2006).