Nutrient Composition and Tannin Contents of Forage Sorghum, Cowpea, Lablab and Mucuna Hays Grown in Limpopo Province of South Africa

摘要

The nutrient composition and tannin contents of forage sorghum {Sorghum Sudanese), cowpea (Vigna unguiculatd), lablab {Lablabpurpureus) and mucuna {Mucunapruriens) were determined by chemical methods. The experimental design was a completely randomised design with four treatments: forage sorghum, cowpea, lablab and mucuna hays. All the legume species had higher (p<0.05) protein contents than sorghum hay, ranging from 18-22%. Within the legume species, cowpea hay had higher (p<0.05) protein content than lablab and mucuna hays. Similarly, lablab hay had higher (p<0.05) protein content than mucuna hay. Sorghum hay had higher (p<0.05) NDF and ADF values than the legume species. Mucuna hay had higher (p<0.05) concentrations of both condensed tannins andhydrolysable tannins than cowpea, lablab and sorghum hays, while lablab hay had the highest (p<0.05) concentrations of total polyphenols. Among the legume species, mucuna hay had higher (p<0.05) NDF and ADF values than lablab hay, while those of cowpea and lablab hays were similar (p>0.05). Legumes have the potential of being utilised as protein supplements for ruminants on low quality roughages. However, tannins in legumes may have both negative and positive effects on diet intake, digestibility and palatability. There is, therefore, need to evaluate these legumes when used as protein supplements for ruminants on a basal diet of sorghum hay.