Lima bean seeds
The nutritive value of lima bean seeds is difficult to assess due to the lack of available information. A 1945 report gave a rather high in vivo OM digestibility of 84% (measured in sheep), corresponding to an ME value of 12.2 MJ/kg DM (Woodman, 1945), which is consistent with what is generally observed for legume seeds. A 2010 study reported much lower values, with an OM digestibility (gas production method) of 50% and an estimated ME of 8.8%. Those values were similar to those obtained with jack bean (Canavalia ensiformis), but much lower than those obtained with other tropical legumes grains, including African yam bean (Sphenostylis stenocarpa), cajan pea (Cajanus cajan), sword bean (Canavalia gladiata), lablab (Lablab purpureus), bambara groundnut (Vigna subterranea) and soybean (Glycine max), which led to the conclusion that lima bean was unsuitable as a protein supplement for ruminants. However, this study also reported large and somehow inconsistent figures for fibre, indicating that more research is clearly needed (Ajayi et al., 2010).
Pods from varieties with uncoloured seeds can be fed to goats and sheep (Göhl, 1982).
Lima bean forage
Lima bean provides fodder, including hay and silage.
Reported OM digestibility values range from 56% (gas production) to 68% (in vivo), corresponding to ME values of 8.4 and 9.2 respectively (Ajayi et al., 2009; Phillips et al., 1946). Lima bean vines fed to sheep had a slightly higher DM digestibility than pea vines (65 vs. 63%) but were less palatable, probably due to their slightly higher lignin content (6.4% vs. 6.1%) and lower lignin digestibility (11% vs. 16%) (Davis et al., 1947).
Cattle and sheep
In the early 20th century, lima bean straw (dried vines left after the harvest) used to be a valued livestock feed for cattle and sheep in Southern California. Its nutritive value was considered to be comparable to that of cereal and grass hays. It was suggested that it be fed in combination with alfalfa hay in order to increase its protein content (Woll, 1915).
Dairy cows can be fed on lima bean vines (with or without seeds). Vines should be chopped in order to enhance palatability. Young vines cut when the leaves were still green resulted in higher intake resulting in a more nutritious diet. It was also possible to use leftover vines after pod harvest (Haenlein et al., 1965). Young vines are easily made into silage (Ishler et al., 2010). Silage made out of leftover vines could be fed to growing and milking cattle. However it had relatively low digestible energy and required more energy supplementation than maize silage (Haenlein et al., 1965). It is recommended to limit the feeding of bean silage to 60 to 80% of the usual intake for forage dry matter (Ishler et al., 2010).
In Nigeria, a silage made of young lima bean vines (before flowering), fresh Napier grass (Pennisetum purpureum) and pineapple pulp increased dietary protein content, nutrient digestibility, nitrogen absorption and retention, and also reduced weight loss of goats during the dry season (Ajayi, 2011). In a comparison of such silages made from the vines of either lima bean, cajan pea or African yam bean, the silage based on lima bean produced the optimal growth rate and weight gain in the goats (Ajayi et al., 2012).