Herbage Dry Matter Production, Crude Protein Yield and Nutritive Value of Elite Cowpea (Vigna Unguiculata L. Walp) Accessions Grown Under Sub-Humid Climatic Conditions of Western Oromia, Ethiopia

摘要

Four elite accessions of Vigna unguiculata (V. unguiculata ILRI 9325, V. unguiculata ILRI 11976, V. unguiculata ILRI 6782 and V. unguiculata ILRI 6783), selected from prior advanced regional forage variety trials were evaluated for herbage dry matter (DMY) and crude protein (CP) yields (CPY), and quality traits alongside with a standard cow pea cultivar, V. unguiculata WWT as a check. Four of the accessions (V. unguiculata ILRI 9325, V. unguiculata ILRI 6782, V. unguiculata ILRI 6783 and V. unguiculata WWT) gave significantly higher and comparable herbage DM (P<0.01) and CP yields (P = 0.05), with V. unguiculata ILRI 9325 giving significantly higher yields for both traits. Averaged over the accessions, the CP content was 17%, with values ranging from 16% for V. unguiculata WWT to 18% for V. unguiculata ILRI 9325. The overall mean neutral detergent fiber (NDF), acid detergent fiber (ADF) and acid detergent lignin (ADL) contents were 43%, 34% and 6%, respectively. The in vitro organic matter digestibility (IVOMD) values ranged from 64% for V. unguiculata ILRI 6783 to 69% for V. unguiculata WWT, with an overall mean of 67%. Similarly, the relative feed value (RFV) index averaged 135, with values ranging from 128 for V. unguiculata ILRI 6782 to 142 for V. unguiculata WWT. The mean metabolizable energy (ME) content (MJ kg-1 DM) was around 10 MJ with values varying from 9.5 MJ for V. unguiculata ILRI 6783 to 10.4 MJ for V. unguiculata WWT. In view of the herbage DM and CP yields and concentration of the various forage quality traits, two of the top ranking accessions combining high DM and CP yields and superior quality attributes were: V. unguiculata ILRI 9325 and V. unguiculata ILRI 11976. The cultivar, V. unguiculata WWT, used as a standard check in this experiment ranked third. The two best performing accessions can thus be promoted to the next variety verification stage alongside with V. unguiculata WWT as a standard check to finally identify one or two alternative V. unguiculata varieties for official release.