Chemical composition of toasted and fermented earth ball (Icacinia manni) meals: Determination of their feeding value using broiler chickens
The study compared the chemical composition of fermented and toasted Icacina manni meal and evaluated their feeding and economic values using broiler chickens. The harvested roots were processed under two methods: the first involved peeling, chopping and fermentation of the roots for 48hours, while in second method, peeled tubers were grated and the liquid component squeezed out prior to toasting. Three diets each were formulated at starter and finisher phase of production, with diet one as the control. Diets two and three had 30% of maize replaced by fermented I. Manni and toasted I. manni meals, respectively. One hundred and thirty five day old broiler chicks were divided into three groups of forty five chicks, randomly allocated to the three experimental diets in a completely randomized design and fed for 28 days each of starter and finisher phase. Data generated were analysed using the general linear models procedure of SPSS options, Version 18.00 (SPSS Inc., 2010). The result revealed that I. manni samples were similar (P>0.05) to maize in ash and carbohydrate components. The processing methods significantly (P<0.05) reduced the levels of anti-nutrients in the samples, except for phytates, with the fermentation method causing the highest reduction in the anti-nutrients levels. At the starter phase, birds on control diet recorded superior (P<0.05) average daily feed intake and weight gain while the feed conversion ratio (FCR) values were not influenced by the treatment at both phases of production. The dressing percentage and relative weights of the cut parts and internal organs were not (P>0.05) influenced by the treatment. The dietary inclusion of I. manni meals reduced the cost of feed production by 50%, the cost of feed consumed from ₦ 135.96 to ₦ 42.35 and ₦ 57.41 in toasted and fermented I. manni diets, respectively and the cost of producing a kilogram of meal at the starter phase. From the economic perspective, it was concluded that toasting could serve as an alternative method of processing I. manni meal for poultry feeding.
Key words: Anti-nutritional factors, toasting, fermentation, Icacina manni, performance, carcass characteristics.