Nutritive value of false yam (Icacina oliviformis) tuber meal for broiler chickens

Abstract

False yam (Icacina oliviformis syn. Icacina senegalensis) is a drought-resistant plant in West and Central Africa that produces a large tuber with a high starch content, but it contains antinutritive factors (terpenes). The objective was to evaluate its feed value for broilers when the tuber was sun-dried (SFYTM) or boiled (BFYTM). In experiment 1, the tubers were peeled, diced, sun-dried (5 d), and milled. In experiment 2, the diced tubers were boiled (2 h), dried (8 d), and milled. Each meal was substituted for corn (Zea mays, wt/wt basis) at levels of 0, 3, 6, and 9% in a basal broiler grower diet (21% CP; 2,967 kcal/kg of ME) and fed to broiler chicks from 21 to 56 d of age, using a completely randomized design (4 treatments, 3 replicates). Each replicate had 10 chicks. Nutrient concentrations (% of DM) of SFYTM were CP (5.41), ether extract (1.60), NDF (28.61), starch (48.63), ash (2.19), and gross energy (4,067 kcal/kg of DM), and those of BFYTM were CP (6.46), ether extract (0.98), NDF (32.37), starch (43.12), ash (2.76), and gross energy (4,139 kcal/kg of DM). The contents of total resins in the meals ranged from 2.28% (BFYTM) to 3.75% (SFYTM). In experiment 1, increasing the dietary level of SFYTM linearly (P < 0.001) decreased feed intake (P < 0.001), BW gain (P = 0.004), G:F (P = 0.041), and dressed carcass yield (P = 0.011). However, in experiment 2, no differences were observed in growth performance (P > 0.05) between any of the dietary treatments. In both experiments, mortality was 2.00% or less (P > 0.05). Inclusion of each meal in the diets did not affect the health of the birds, and no adverse changes in blood hemoglobin, hematocrit, and white blood cells were observed.