FOLIAGE YIELD, CHEMICAL COMPOSITION AND INTAKE CHARACTERISTICS OF THREE MUCUNA VARIETIES

The effect of variety and fertiliser on foliage yield and chemical composition of the foliage of three mucuna varieties, Mucuna deeringeana, Mucuna cochinchinensis and Mucuna spp. var, Ghana, was studied in an experiment in Burkina Faso in 2005 and 2007. The chemical composition and intake of hay from the same mucuna species were also studied using six Zebu cows per treatment offered 1/3 of their diet as grass hay. The experimental design of the agriculture experiment in both years was a randomised block with 3 mucuna varieties, not fertilised or fertilised with 2 kg DM/m2 of cow manure and with 4 replications. The foliages were harvested when 75% of the plants were flowering both for measuring foliage yield and for making hay. Soil characteristics before and after the experiment, dry matter yields and stem/leaf ratio of the vines were recorded and chemical composition of the foliages analysed. The mean age at harvesting was 57 d for M. spp. var. Ghana that was significantly shorter than for M. deeringeana (63 d) and M. cochinchinensis (81 d). Age at harvesting was not significantly affected by fertilisation. Dry matter yield was significantly lower for M. spp. var. Ghana, 1.71 t/ha for the unfertilised plots, compared to 3.29 and 3.07 t/ha for M. deeringeana and M. cochinchinensis, respectively. Fertilisation with manure more than doubled the yield for all varieties. There was no difference in stem/leaf ratio due to variety or fertiliser. The leaves+petiole fraction was generally heavier than the stem fraction. M. spp. var. Ghana had significantly higher content of crude protein than M. deeringeana and M. cochinchinensis (204, 177 and 150 g/kg DM, respectively). M. cochinchinensis had significantly higher ADF content than M. spp. var. Ghana, 474 and 369 g/kg DM, respectively. M. spp. var. Ghana had the highest CP content (209 g/kg DM), significantly different from M. cochinchinensis (165 g/kg DM) but not from M. deeringeana (192 g/kg DM). M. spp. var. Ghana had the best intake characteristics (4659 g and 3668 g/d for cows and heifers, respectively), but significantly so only for cows. In conclusion, the high foliage yield, the possibility of increasing soil fertility through N fixation and the high nutritive value of the foliage makes mucuna an interesting feed for ruminants even in areas with low soil fertility and a short rainy season