Stylo is a valuable forage legume for ruminants, usually fed as hay (or sun-dried), cut-and-carry forage, or grazed. Like other legumes, Stylosanthes guianensis is often used as a supplement during the dry season to improve the nutritive value of low quality forages, including crop residues or by-products such as rice straw (Thang et al., 2010), maize stover (Said et al., 1993), or other locally available forages (Matizha et al., 1997; Akinlade et al., 2002; Kiyothong et al., 2004; Pen et al., 2013).
The palatability of Stylosanthes guianensis increases with maturity. Fresh young stylo is not very palatable to livestock, possibly due to the bristles borne on the stems (Skerman et al., 1990; FAO, 2014). Stylo has a low palatability during the rainy season, but is readily eaten in the dry season. If kept short, it does not become woody but remains leafy and palatable (Göhl, 1982). Satisfactory intake was observed in zebu cattle when stylo was fed fresh as a supplement (Pen et al., 2013). Stylo seems to be more palatable when it is wilted before being stall-fed to cattle (Skerman et al., 1990; FAO, 2014).
The OM digestibility of Stylosanthes guianensis ranges between 51 and 67% which is low compared to other tropical legumes (Gardener et al., 1982; Mupangwa et al., 2000; Magalhaes et al., 2003). It has a high proportion of moderately soluble proteins compared with other tropical legumes (Magalhaes et al., 2003).
In Thailand, Stylosanthes guianensis hay used in association with cassava hay in moderate amounts (1-2 kg/d), as a supplement for dairy cows fed a basal forage of moderate quality reduced significantly the amount of concentrate without altering milk production (Kiyothong et al., 2004).
In Cambodia, the inclusion of 30% fresh Stylosanthes guianensis significantly improved OM intake in zebu steers, allowing a better utilisation of a low protein basal diet by improving the efficiency of microbial protein production in the rumen (Pen et al., 2013). In Vietnam, with crossbred (Yellow x Sindhi) growing cattle fed a basal diet of urea-treated straw, molasses and concentrates, supplementation with 1 kg/d sun-dried Stylosanthes guianensis or a 50:50 mixture or Stylosanthes and cassava foliage resulted in intake, OM digestibility and live-weight gain comparable (though slightly lower) to that obtained with soybean meal supplementation, but N retention was lower. Results with stylo supplementation were higher than those obtained with cassava hay (Thang et al., 2010).
In Zimbabwe, when offered as a sole forage to adult sheep, Stylosanthes guianensis hay was well ingested and fully covered their energy and N requirements for maintenance. Intake was higher than for Cassia rotundifolia and similar to that of lablab (Lablab purpureus) and Macroptilium atropurpureum (Mupangwa et al., 2000).
With growing sheep, the inclusion of 30% or more of Stylosanthes guianensis hay in the diet of growing lambs fed poor quality forage substantially increased their intake, OM digestibility and live-weight gain (Ethiopia, Said et al., 1993; Zimbabwe, Matizha et al., 1997; Nigeria, Akinlade et al., 2002). In comparison trials with other legume hays, Stylosanthes guianensis hay was better than Macrotyloma axillare (Said et al., 1993), Desmodium intortum (Said et al., 1993), Desmodium uncinatum (Matizha et al., 1997) and Lablab purpureus (Akinlade et al., 2002); was comparable to Aeschynomene histrix (Akinlade et al., 2002); but was inferior to Macroptilium atropurpureum (Matizha et al., 1997).