In-vitro evaluation of cultivars of tapioga and sweet potato tubers for livestock

Various cultivars of tapioca (Manihot esculenta) and sweet potato (Ipomoea batatas) were evaluated by in-vitro technique. The average yield of tubers in tapioca was higher (P<0.01) than that of sweet potato. There were significant variations (P<0.01) among the cultivars with regard to proximate principles except NFE and EE in case of tapioca and EE in case of sweet potato. Both the tuber crops were deficient in all the minerals. The fresh yield, DM yield, NFE yield, content of CP, EE, NFE, Ca, P, Zn and Co differed significantly (P<0.01) between tapioca and sweet potato tubers. The leaves/vines contained more than 16% protein and the level of CF and CWCs was lower than cultivated fodders. The IVDMD/IVOMD and ME content of leaves was 60% and 7.5 MJ/kg DM respectively and were richer in minerals compared to tubers. In conclusion, the tubers were rich in soluble carbohydrates and very low in protein, fibre and mineral elements. The tapioca cultivars viz., H-226, H-1687, H-165 and Sree Jaya and sweet potato cultivars viz., Gouri, 440038 and 442074 could serve as energy sources, alternate to grains but need to be supplemented with protein and minerals when used in the diets of livestock and poultry.