Gelatinization of fermented cassava tuber meal and its nutritive value for broilers

Abstract

The effect of fermentation of cassava tuber followed by its gelatinization was evaluated as a method of processing cassava for use as source of energy in broiler diets. Peeled and unpeeled cassava tubers were separately fermented in water for 4 days, dried in the sun and then milled to produce fermented peeled and unpeeled cassava tuber meals, respectively. The dusty meals were then gelatinized by mixing with water in pots seated over fire at the rate of 1kg of cassava tuber meal to one litre of water and stirred until they gelatinized into fufu. The gelatinized pastes were then taken bit by bit and flattened on polythene sheets and dried in the sun. The resultant fermented and gelatinized peeled and unpeeled cassava tuber cakes were then milled to produce fermented and gelatinized unpeeled cassava tuber meal (UFGC), a brownish-looking non-dusty product and fermented and gelatinized peeled cassava tuber meal (PFGC), an ash-looking non-dusty product. Three broiler diets were made such that diet 1 (control) contained maize as source of energy, while in diets 2 and 3, the maize in the control diet was completed replaced with UFGC and PFGC, respectively, both in the starter and finisher diets. One hundred and twenty (120) broiler chicks were divided into 3 groups of 40 birds each and each group assigned to one of the diets, using completely randomized design, and fed for 4 weeks with the starter diets and finisher diets for another 4 weeks. At the starter phase, the UFGC diets gained significantly (P < 0.05) less weight and consequently had poorer feed conversion ratio. There were no significant differences in feed intake (P < 0.05). At the finisher phase, the group on UFGC gained significantly (P < 0.05) more body weight. The groups on cassava diet tended to consume less feed and so had better feed conversion ratio. There were no differences (P > 0.05) in dressed weights and weights of internal organs but the group on PFGC diet accumulated significantly (P < 0.05) more abdominal fat.

Keywords: Broiler, Cassava, diet, fermentation, gelatinization.