published_or_final_version / Botany / Doctoral / Doctor of Philosophy

Thesis (Ph. D.)--University of Hong Kong, 2001. / Includes bibliographical references.

Forage of beta-carotene-fortified orange-fleshed sweet potato is essential for alleviation cattle malnutrition. The study aims were to determine effects of supplementing sweet potato (SP) roots and sun dried forage on degradation of dietary legumes, intake and milk yield in dairy cattle. Mature SP roots were oven dried and forage vines and leaves (V&L) sun dried. Lactating dairy were supplied meals with total mixed ration (TMR) constituting varying levels of sweet potato forage and concentrate. The SP flour was rapidly and completely degraded In Sacco while degradability of V&L was comparable to that of Lucerne hay. Rumen degradation of Lucerne was reduced when the legume was incubated proximal to SP. Substitution of TMR with fresh SP forage and flour meal increased degradability of diets. Glucose post-feeding was increased (P<0.05) by SP roots but no change in milk yield. Orange-fleshed SP forage is recommended for improving energy supply in lactating cow diets / Agriculture and  Animal Health / M. Sc. (Agriculture)

Forage of beta-carotene-fortified orange-fleshed sweet potato is essential for alleviation cattle malnutrition. The study aims were to determine effects of supplementing sweet potato (SP) roots and sun dried forage on degradation of dietary legumes, intake and milk yield in dairy cattle. Mature SP roots were oven dried and forage vines and leaves (V&L) sun dried. Lactating dairy were supplied meals with total mixed ration (TMR) constituting varying levels of sweet potato forage and concentrate. The SP flour was rapidly and completely degraded In Sacco while degradability of V&L was comparable to that of Lucerne hay. Rumen degradation of Lucerne was reduced when the legume was incubated proximal to SP. Substitution of TMR with fresh SP forage and flour meal increased degradability of diets. Glucose post-feeding was increased (P<0.05) by SP roots but no change in milk yield. Orange-fleshed SP forage is recommended for improving energy supply in lactating cow diets / Agriculture and  Animal Health / M. Sc. (Agriculture)