LABLAB (LABLAB PURPUREUS) AND LUPIN (LUPINUS-ANGUSTIFOLIUS) SEEDS AS SUPPLEMENTS FOR SHEEP FED LOW-QUALITY ROUGHAGE

The seeds of lablab (Lablab purpureus) and lupin (Lupinus angustifoliu s) were investigated as supplements for young sheep. In experiment 1, rumen-cannulated sheep were offered low quality roughage ad libitum al one or supplemented with about 5, 10 or 20 g/kg liveweight whole lupin or lablab seed. Rumen ammonia concentrations were increased by each l evel of both supplements, and the increases were greater with lupins t han with lablab. The pH of rumen fluid was decreased by both supplemen ts, particularly when the higher levels were fed. Dry matter of broken seeds of both legume species rapidly disappeared from synthetic fibre bags incubated in the rumen. Roughage dry matter disappearance from s ynthetic fibre bags decreased (P < 0.05) when 20 g/kg liveweight lupin s was fed, and this level of both supplements reduced (P < 0.05) rough age intake. Total dry matter intake was increased more by lablab than by lupins, but dry matter and organic matter digestibility tended to b e increased to a lesser extent by lablab. Overall, digestible organic matter intake and liveweight gain were increased to similar extents by both supplements. Wool growth was lower (P < 0.05) with lablab than l upins, particularly at the highest level of supplementation, suggestin g that availability of some amino acids was lower with lablab suppleme nt. In experiment 2, rumen-cannulated sheep were fed low quality rough age ad libitum and supplemented with about 10 g/kg liveweight of eithe r lupin or lablab seed. Lectins and protease inhibitors present in the lablab seed disappeared rapidly from synthetic fibre bags incubated i n the rumen. In conclusion the nutritional value of lablab seed as a s upplement for sheep fed low quality roughage was similar to that of lu pin seed for liveweight gain, but was lower for wool growth.