Chemical composition, gas production and degradation characteristics of haulms of improved dual purpose Cowpea (Vigna unguiculata l. walp) cultivars

The study investigated the chemical composition and the nutritive value of four improved cultivars of cowpea (Vigna unguiculata L. Walp) haulm using both in situ disappearance (ISD) and in vitro gas production (IVGP) techniques. The DM and CP disappearance were examined using a split-plot design to compare the effects of cultivar and haulm fraction as well as their interactions. The highest gas production was observed in the cultivar IT93K-2045-93. All the cultivars had similar pools of digestible fibre and disappeared at the same rates. In a test that included separated leaves and stems, IT93K-204593 had a larger soluble fraction and leaves had larger pools of soluble and digestible fiber that disappeared at greater rates than stems. Assessment of CP degradation showed that cultivar IT93K-2045-93 had a greater percent soluble material than IT93K-2309. The amount of ruminal digestible protein (RDP) was greater in IT93K-2309 than in IT93K-2045-93, however, the latter disappeared at greater rates than the former. Cultivars IT93K- 2045-93 and IT93K-2309 may prove to be desirable supplements for small ruminants receiving a poor quality basal diet such as maize stover especially during the lean season when feed is limiting.