COMPARATIVE FEEDING VALUE OF FORAGES FROM 2 CEREAL-LEGUME BASED CROPPING SYSTEMS FOR BEEF-PRODUCTION FROM CROSSBRED (BOS-TAURUS X BOS-INDICUS) STEERS AND SUBSEQUENT PERFORMANCE OF UNDERFED AND REALIMENTED STEERS

Foods produced from tow cereal-legume cropping systems were evaluated in a 250-day growth trial using Friesian X Boran crossbred steers. Cro ps and crop combinations in cropping system 1 were oat-vetch (Avena sa tiva-Vicia dasycarpa; OV), wheat-trifolium (Triticum aestivum-Trifoliu m steudneri; WT), teff (Eragrostis tef) adn chickpea (Pisum sp). Cropp ing system 2 differed from 1 in that maize-lablab (Zea mays-Lablab pur pureus; ML) replaced wheat-trifolium. Twenty-four steers (mean initial live weight 157 (s.d. = 4.5) kg were assigned randomly within weight group to four treatments. Treatments comprised ad libitum teff straw ( TS) given alone (T1), TS plus wheat middlings (WM) given at 0.01 M (bo dy weight) (T2), forages from system 1 fed in the order OV, WT and TS plus chickpea for 135, 48 and 67 days respectively (T3) or forages fro m system 2 fed in the order OV, ML and TS plus chickpea for 73, 147 an d 30 days respectively (T4). The feeding period for each crop of T3 an d T4 was based on its contribution to the total dry matter (DM) yield of the cropping system. Apparent digestibility of DM measured by the a cid-insoluble ash method was higher (P<0.05) for T3 and T4 than for T2 . DM intake was higher (P<0.01) for steers on T2 resulting in 1 kg hig her daily intake of digestible DM than for T3 and T4. Steers on T4 gai ned (average daily gain, ADG) more (P<0.01) weight than steers on T3 ( 149 v. 85 g per head per day) but less (P<0.01) than those on T2 (528 g per head per day). Steers on T1 lost 94 g per head per day. Food eff iciency (kg gain per kg food) followed a similar trend as ADG. At the end of the trial, two steers from each treatment were slaughtered for carcass assessment and the remaining steers used in a realimentation s tudy of 120 days and then slaughtered for carcass assessment. Steers w hich gained poorly during 250-day trial (T1, T3 and T4) exhibited comp ensatory gains of 497,550 and 565 g per head per day respectively comp ared with 398 g per head per day for steers on T2. Carcasses from T2 y ielded significantly more (P<0.05) lean and fat than carcasses from T3 and T4. The results suggest that growing food crops in association wi th legumes has the potential of increasing cattle performance.