Characterization of Elite Cowpea (Vigna Unguiculata L. Walp) Accessions Grown Under Subhumid Climatic Conditions of Western Oromia, Ethiopia: Herbage and Crude Protein Yields and Forage Quality

Five elite cowpea accessions (ILRI 9325, ILRI 11976, ILRI 6782, ILRI 6783 and WWT) were evaluated for herbage dry matter (DMY) and crude protein (CPY) yields, and nutritive value. Among the tested accessions, ILRI 9325, ILRI 6782, ILRI 6783 and WWT gave higher and comparable yields (P < 0.01 for DMY; P=0.05 for CPY), with ILRI 9325 giving superior yields. The overall CP content was 17% with a range of 16% for WWT to 18% for ILRI 9325. The overall mean for neutral detergent fiber (NDF), acid detergent fiber (ADF) and lignin were 43%, 34% and 6%, respectively. The in vitro organic matter digestibility (IVOMD) ranged from 64% (ILRI 6783) to 69% (WWT). The relative feed value (RFV) index averaged 135 (range = 128 – 142). The mean metabolizable energy (ME) content was 10 MJ/kg DM with a range of 9.5 to 10.4. Three accessions that combined high biomass DM and crude protein yields, and herbage quality were: ILRI 9325, ILRI 11976 and WWT. The two former accessions can thus be promoted to the next variety verification stage alongside with WWT as a check to identify one or two alternative cowpea varieties for official release.