Taro species (Alocasia odora (C) Koch, Xanthosoma nigra (Vell I)Stellfeld and Colocasia esculenta  (L) schott) ) in Central Vietnam: biomass yield, digestibility and nutritive value

Du Thanh Hang,  N V Binh  and  Preston T R

HUAF, Hue, Vietnam
hangduthanh@yahoo.com.vn

Abstract

Four varieties of three species of taro were grown in the same condition to investigate the biomass yield at three harvesting intervals (after growing 90 days and then at 40 days interval). The productivity was highest in Chia voi, Ao trang (Colocasia esculenta  (L) schott)) (26 tonnes/ha) , and then Tim (Alocasia odora (C) Koch) (23.3 tonnes/ha) and lowest  in Mon Quang (Xanthosoma nigra (vell) Stell feld) (11 tonnes/ha). The biomass yield was highest in the second cutting. Oxalate content was reduced by the age decreasing from 2.29 to 1.69% in DM in leaves and from 4.05 to 2.6% in DM of stem. 

Four castrated male pigs (MCxLW) with initial weight of 40 kg were used to study the total tract digestibility and nitrogen (N) utilization of diets including 50% ensiled taro forages (in DM). Comparisons were made of addition of 0.2% methionine; or 5% wine by-product or no addition; and with  a control diet with only maize and rice bran. The experimental design was a 4*4 Latin square. Digestibility was highest in the diet with added 5% wine by-product (78%). Diets with added methionine or not had digestibility of 66-68%. Nitrogen retention was highest in the diet with 5% wine by-product (19 g/day/) compared with other diets (9.7-9.9 g/day). Addition of 5% wine by-product in a diet with 50% ensiled taro forage diet increased the biological value of the protein from 66% to 77%.

Key words: Biomass, yield, taro forage, oxalate, digestibility, retention, wine by-product, methionine, ensiled taro forages.