Pasture and fresh fodder
Vigna mungo grown as green fodder and fed to adult Red Sindhi cattle as the sole source of feed was found to be palatable. Dry matter intake was 18.4 g/kg body weight. The N balance was positive but the Ca and P balances were marginally negative. It was concluded that Vigna mungo fodder was nutritious but required mineral supplementation (Saha et al., 1981). In Bangladesh, some dairy cattle feeding systems are based on legume pastures, combining Vigna mungo and Lathyrus sativus herbage with copra meal-based concentrates. Supplementing such diets with straw (2.5 kg/h/day) did not change DM intake but increased milk production (up to 8.64 L/d) and was more profitable (Islam et al., 1995).
Reported OM digestibility values in cattle varied between 57 and 73% (Harrison, 1942; Saha et al., 1981).
The crude protein of Vigna mungo straw was found to be more degradabale to that of Leucaena leucocephala leaves (Singh et al., 2002). Dry matter is also highly rumen-degradable (Reddy, 1997). OM digestibility of the roughage was good (68%), and ME estimated from gas production (9.1 MJ/kg DM) was higher than that of rice straw and groundnut straw (Krishnamoorthy et al., 1995).
However, using black gram straw as a sole feed ad libitum did not meet the nutritional requirements (and particularly the protein requirement) of Murreh Buffalo heifers (Sanjiv Kumar et al., 1995). Vigna mungo straw offered to sheep at 60% of the diet supported growth in sheep (average live-weight gain of 60-62 g/h/day), and was equivalent to wheat straw in terms of feed efficiency and feeding cost (Jadhav et al., 2001).
There is no recent information concerning the use of Vigna mungo seeds in ruminants. Early research found the seeds to be relatively digestible in cattle (OM digestibility of 65%) (Sen, 1938 cited by Göhl, 1982).
In India, black gram chuni was found to be palatable to buffaloes, and it was possible to include up to 40 % of chuni in the concentrate diets of male buffaloes also fed rice straw, with no effect on OM, DM and crude protein digestibility and with a positive effect on fibre digestibility (Reddy et al., 2000). At a 40% level, the degradability of DM and CP was estimated to be 55.6% and 71.6% respectively (Reddy et al., 2002).
In Bangladesh, black gram bran (100 g/d) given to goats fed fresh grass was found to be a potentially valuable supplement, resulting in a higher protein intake and higher weight gain (57 vs. 31 g/d in goats fed grass alone) (Islam et al., 1997).