The nutritive and economic potential of cowpea (Vigna unguiculata and lablab (Lablab purpureus) legume hay as supplements to sun-cured corn (Zea mays indentata) stover

Cowpea (CWP) and lablab (LAB) were evaluated as potential supplements to corn stover (CS) fed for ad libitum intake to sheep. Cowpea and LAB were supplemented separately or as a mixture at 282.2 g/d in Experiments 1, 2, and 3. Degradation and passage kinetics, intake and digestion of nutrients, and rumen metabolites were measured. Experiments 4 and 5 consisted of supplementing CS with CWP at 133.9, 267.5, 397.1, and 524.5 g/d. Intake and digestion of nutrients, rumen metabolites, microbial nitrogen, growth, and economics were studied. Nitrogen and minerals in CWP and LAB were adequate for sheep. Supplementation increased (P .05). Nutrient intake and digestion of lambs in Experiment 4 increased linearly with CWP supplementation. Ruminal concentrations of volatile fatty acids, ammonia nitrogen, and pH level were increased (P <.01) by supplementation. Concentrations of ammonia nitrogen was maintained above 115.4 mg/l for up to 10 h when the 68.76, weight loss of 17.8 g/d, and death of three lambs from diets containing CS alone. Daily weight gain was increased (P < .01) with CWP supplementation. Economic loss reduced from 68.76 to \13.09 at the lowest level of CWP and profit increased to 1.69 at the highest level of CWP supplementation. Lower N and mineral content of CS was considered responsible for the weight loss and death of non-supplemented lambs. Lambs supplemented with increasing quantities of CWP twice daily had a continuous release of feed N in the rumen for most of the day which could explain their higher feed intake, weight gain, and consequent profitability. Improvement in CS degradation and nutrient utilization through supplementation indicated that CWP and LAB were potential supplements for low quality roughage. Supplementation of CWP was economical at all level with reference to prevention of death, weight loss of lambs, and higher incremental returns from CWP.