THE EFFECT OF SUPPLEMENTING TEFF (ERAGROSTIS-TEF) STRAW WITH GRADED-LEVELS OF COWPEA (VIGNA-UNGUICULATA) AND LABLAB (LABLAB-PURPUREUS) HAYSON DEGRADATION, RUMEN PARTICULATE PASSAGE AND INTAKE BY CROSSBRED (FRIESIAN X BORAN (ZEBU)) CALVES

This study characterized the degradability of cowpea (Vigna unguiculat a) and Dolichos lablab (Lablab purpureus) hays (trial 1) and the effec t of these legumes on rumen ammonia concentration (RAG), particulate p assage rate (k(1)) and intake (trial 2) and the degradability of teff (Eragrostis tef) straw (trial 3). Trials 1 and 3 were conducted using ruminally cannulated crossbred (Friesian x Boran) cows. In trial 1, co ws were fed native pasture hay ad libitum plus 2.45 kg cottonseed cake head(-1) day(-1). In trial 2, calves were fed ad libitum teff straw a lone or supplemented with three levels (0.5, 1 and 1.5% of body weight ) of either cowpea or lablab hay. In trial 3, cows were fed teff straw ad libitum supplemented with either cowpea or lablab hay at 1% of bod y weight. Cowpea had similar degradation characteristics to lablab. Su pplementation increased RAC (154-218 vs. 48 mg/l; P<0.01), rate of deg radation of teff straw (0.0257-0.0274 vs. 0.0138/h; P<0.05), rumen out flow rate (k(1)) (1.48-2.09 vs. 1.18%/h; P<0.05) and decreased the mea n retention time (MRT; 72.8 vs. 109 h; P<0.01). Total dry matter intak e (DMI) increased with increasing level of supplementation. Cowpea and lablab had similar RAG, rate of degradation of teff straw, k(1), MRT and DMI. It was concluded that both herbaceous legumes are equally eff icient in alleviating nutrient deficiencies incurred when teff straw i s fed to calves.