Hairy vetch can be grazed, especially in annual legume-grass and/or legume-cereal mixtures. It can also be offered as hay or silage to supplement cereal or grass based diets.
Hairy vetch is not very palatable to livestock (SARE, 2008). When compared to several clover species (Trifolium incarnatum, Trifolium vesiculosum, Trifolium nigrescens, Trifolium hirtum) in cafeteria-style trials with goats, hairy vetch was shown to be of intermediate palatability (Terrill et al., 2004).
Digestibility and energy values
In cattle, in situ OM degradability of hairy vetch hay was 69% (Getu Kitaw et al., 2010). In rams, in situ DM degradability of hairy vetch straw was between 59 and 61% (Bruno-Soares et al., 1997; Abreu et al., 1998; Bruno-Soares et al., 2000). Voluntary intake of hairy vetch hay in rams was 71 g/kg LW0.75, OM digestibility was 50% and ME was 6.6 MJ/kg DM (Abreu et al., 1998).
In a Finnish organic dairy system based on pasture associated with Italian ryegrass (Lolium perenne) and barley, hairy vetch was better utilized than common vetch (Vicia sativa) for extended grazing, and produced more herbage. Dairy cows grazing hairy vetch produced a similar amount of milk as cows grazing Persian clover (Trifolium resupinatum) (20.6 vs. 22 kg/d), in spite of the lower in vitro OM digestibility (74 vs. 78%) and sugar content (8.6 vs. 13.6% DM) of the hairy vetch. Unlike clover, hairy vetch did not cause bloat (Kuusela et al., 2004).
In Ethiopia, hairy vetch hay fed to lactating dairy cows replaced up to 50% of a concentrate mix without changes in feed intake, nutrient digestibility, milk yield and milk composition. DM digestibility and ME intake were higher in diets including 50% of hairy vetch hay than for diets containing 25% or 75% hay (Getu Kitaw et al., 2010).
In Mexico, a silage of hairy vetch (Vicia villosa) intercropped with perennial ryegrass (Lolium multiflorum) used to supplement dairy cows on restricted grazing resulted in similar productivity as maize silage, but the economic return was 9% lower (Hernandez-Ortega et al., 2011).
In the USA (Oklahoma), stocker cattle grazing tall fescue (Festuca arundinacea) and a legume mixture including hairy vetch had average daily gain (700 g/d) and total gain (296 vs. 237 kg/ha), comparable to cattle grazing fertilized fescue. However, after 3 years, the fescue-legume pasture showed a tendency toward a lower than expected net return compared to the fertilized system (Interrante et al., 2012). In Finland, supplementing growing dairy bulls with a silage made of hairy vetch and whole crop barley, replacing a moderately digestible grass silage, resulted in similar growth performance and carcass characteristics, but supplementing with a hairy vetch-whole crop wheat silage decreased carcass gain due to lower energy intake and poorer feed conversion (Huuskonen et al., 2010). In China, a concentrate feed with 40% hairy vetch was shown to improve the meat quality of hybrid beef cattle, but it is unclear whether the seeds or the foliage were included (Han et al., 2012).
In Pakistan, sheep grazing hairy vetch pasture had the same DM intake as sheep grazing barley pasture during the pre-flowering stage, but DM intake and weight gain were lower for vetch during the flowering and mature stages (Shahid et al., 1993). In Australia, sheep grazing hairy vetch (1 sheep/10 kg available DM) showed higher daily gains than sheep grazing oat pasture (146 vs. 92 g/d) (Spurway et al., 1974).
In Kenya, hairy vetch hay given to sheep (127 g DM/d) as a protein supplement to fresh Sorghum x almum forage resulted in higher DM intake, protein intake, average daily gain and feed efficiency ratio than feeding Sorghum x almum alone (Lanyasunya et al., 2007d). In another trial with fresh hairy vetch, the same authors found that while Vicia villosa had potential as a protein supplement for ruminants fed low quality feeds, its proportion in the diet should not exceed 20% (fresh matter basis), as higher rates reduced intake and VFA concentration (Lanyasunya et al., 2007c).