Evaluation of dual purpose cowpea varieties for dry season feeding of ruminant animals

i Summary/Zusammenfassung ii Summary Evaluation of dual purpose cowpea varieties for dry season feeding of ruminant animals Cowpea is of major importance to the livelihoods of millions of people in the tropics. Resource-poor smallholder farmers derive food, animal feed, cash and manure from the crop. Dual purpose cowpea has the potential to function as a key integrating factor in intensifying systems through supplying protein in human diets, and fodder for livestock, as well as bringing N into the farming system through biological fixation. Going beyond its importance for food and feed, cowpea can be regarded as a fulcrum of sustainable farming in regions characterized by systems for farming that make limited use of purchased inputs. Dual purpose cowpea can sufficiently satisfy the tripartite need of providing (i) food for the farmer (ii) fodder for livestock especially during the critical period of the year (dry season) and (iii) fertility replenishment for the soil (through nitrogen fixation) which will ensure sustainable use of the farmer's limited land (for a longer period without much depletion of its nutrients). performance and nutritive quality of some varieties of dual purpose cowpea (Vigna unguiculata L. Walp) grown in marginal land without fertilization. The experiment was arranged in a 2 x 2 factorial design with 2 seasons (wet and dry) and 2 groups (commercial and improved) of cowpea haulm varieties. Three improved (ITA2, ITA6 and ITA8) and three commercial (Oloyin, Peu and Sokoto) cowpea varieties were used for the study. The cowpea varieties were evaluated for biomass and grain yields, green leaf retention, chemical composition, secondary metabolites, in vitro and in sacco degradation. Biomass harvested during the wet season was used in a feeding study involving thirty West African dwarf sheep. The haulms were fed as supplements to a basal diet of Pennisetum purpureum. Sheep fed commercial cowpea haulms had better feed conversion ratio than those fed improved haulms but all the sheep were in positive nitrogen balance. Results from the feeding study showed that inclusion of cowpea haulms in the diet of sheep had no deleterious effects while improving the haematological and serum biochemical variables. Both biomass and grain yields were higher in the improved varieties harvested in the wet season. Improved varieties were able to retain more leaves into the dry season than their commercial counterparts. Secondary metabolites in the haulms were considerably low and of no nutritional significance. The inability to detect condensed and …