Effects of Fermented Whole Cassava Meal on the Performance of Broilers

Abstract

Initially an experiment was conducted to establish the effect of fermentation on the nutrient composition of whole cassava meal. In this experiment chopped whole cassava was fermented using different moisture conditions (aerobic, semi- aerobic and anaerobic) for varying time intervals (day l, 2, 3, 4, 5, 6). The dried Fermented Whole Cassava Meal (FWCM) samples were analyzed for proximate, cyanide (CN) and soluble carbohydrate composition. The moisture condition and the duration of fermentation both affected the nutrient composition of the resulting cassava product. Anaerobic fermentation was the most effective in reducing cyanide content, while at the same time increasing the level of Crude (CF) (P < 0.05). By the fourth day cyanide and protein contents were 10, 28, 0 mg/kg; and 4.78, 4.01, 5.70 percent for aerobic, semi—aerobic and anaerobic fermentations, respectively. Aerobic and semi-aerobic fermentations did not fully eliminate the cyanide even by the sixth day. Crude protein (CP), CN, and glucose content for anaerobic fermentation were: 3.94%, 145 mg/Kg, and 5.62 g/Kg; 5.78%, 5 mg/Kg, 7.5 g/Kg; and 5.01%, O mg/Kg, and 9.12 g/Kg for fresh, three day fermentation and six day fermentation, respectively. Three day fermentation period was adequate to reduce the cyanide below the toxic level (l0 mg/kg) in broiler diets. Anaerobic fermentation of cassava beyond three days results in \ excessive breakdown and leakage of nutrients rendering the product less nutritious. A second experiment was set to ascertain maximum substitution levels of maize grain with FWCM in broiler diets. In this experiment 198 one day old broiler chicks were fed on six different diets over a period of eight weeks. In the diets used, maize was replaced with FWCM at the following levels: 0, 20, 40, 60, 80, and 100 percent. Fish meal and un-decorticated sunflower cake were used as the protein supplements at various levels to compound isonitrogenous starter and finisher diets. Weekly weight gains and feed intakes were recorded and Feed Conversion Efficiency (FCE) was calculated. Performance of broilers from the successive FWCM diets for the starter and finisher phases were: weight gains (g), 607, 488, 597, 674, 621, 582 ; and 1498, 1552, 1377, 1447, 1428 1271 ; feed intake (g), 1028, 1065, 1112, 1097, 1039, 1113 ; and 2933, 2906, 2887, 2930, 2881, 2991; and FCE, 0.59, 0.46, 0.53, 0.61, 0.60, 0.53; and 0.51, 0.53, 0.48, 0.49, 0.50, 0.42, respectively. Final body weights and feed intakes were not statistically different (P < 0.05) although overall FCE for the 100% FWCM substitution level was lower (P < 0.05) than the others. Final body weights were, 2.14, 2.07, 1.99, 2.15, 2.09, and 1.89 Kg for the successive FWCM levels. Thus birds fed on FWCM diets consumed more feed than those fed on maize control. Among the substitution levels examined, broiler performance was best when maize was substituted by FWCM at the level of \ 60%. Diets where maize was replaced wholly by FWCM had lower weight gains, especially during the finishing period. However, total substitution did not adversely affect broiler health.