Calopo is seldom grazed alone and mostly used in mixed pastures with other grasses and/or legumes. Hay and silage are made but no research has been reported.
Palatability and intake
Calopogonium mucunoides has a low to moderate palatability though it is considered more palatable than Calopogonium caeruleum. Calopo is consumed more readily after cattle become accustomed to it. This is the only palatability problem reported (Cook et al., 2005).
Its lack of palatability is due to its hairy stems and leaves, particularly when the plant is fresh (Asongwed-Awa et al., 2002) and calopo will be more readily accepted if it is wilted before being fed to animals (Cook et al., 2005). Palatability improves when the forage matures (Asongwed-Awa et al., 2002). Taste or odour may also play a part: in sheep, where voluntary OM intake of Calopogonium mucunoides was only 400-500 g/d, the addition of taste-modifiers (monosodium glutamate (2% DM fed) and molasses (5%); or with sodium hydroxide (4% w/w or its molar equivalent of potassium hydroxide) resulted in an immediate and sustained increase in OM intake of about 40% (McSweeney et al., 1986).
In vitro digestibility of Calopogonium mucunoides leaves ranges from 58 to 66% depending on the age of regrowth and level of hairiness. High densities of epidermal hairs (34 hairs per mm²) are associated with lower in vitro dry matter digestibility (Cook et al., 2005; Pizarro, 2001).
In Cameroon, lactating zebu cows grazing Calopogonium mucunoides had a milk yield similar to that of cows grazing natural pastures, and much lower to that of cows grazing Stylosanthes hamata. This poor performance was due to a low intake of calopo pasture (resulting probably from palatability issues) that was still manifest even after several days of adaptive feeding (Asongwed-Awa et al., 2002).
In Brazil, Brachiaria decumbens and Brachiaria brizantha pastures oversown with Calopo mucunoides grazed by cattle at 3.1 head/ha resulted in higher live weight gain per animal and per area than the pure grass pastures, averaging 390 and 340 g/steer/day, and 404 and 352 kg/ha/year, respectively. The major contribution of the Calopo was to increase the crude protein content of the animal diet and, consequently increasing animal production, both during the dry period and the wet period. However, the legume percentage decreased linearly from the first to the third year under grazing (Euclides et al., 1998).
The seeds of several tropical legumes, including Calopogonium mucunoides, have potential as feed supplements for ruminants as they are very digestible and rich in nitrogen. In addition Clitoria ternatea and Calopogonium mucunoides appear to have potential as defaunating agents (Odeyinka et al., 2004).