STRATEGIC SUPPLEMENTATION OF CROSSBRED STEERS FED FORAGES FROM CEREAL-LEGUME CROPPING SYSTEMS WITH COWPEA HAY

Forty-four crossbred steers were used in a 252-day trial to assess the feeding value of forages from two cereal-legume cropping systems. Cro pping system I comprised oat-vetch (Avena sativa-Vicia dasycarpa), whe at-trifolium (Triticum aestivum-Trifolium steudneri), teff (Eragrostis tef) and cowpea (Vigna unguiculata). Cropping system 2 had maizee-lab lab (Zea mays-lablab purpureus) instead of wheat-trifolium. Treatments comprised ad libitum teff straw alone (TI), teff straw plus wheat mid dlings (T2) forages from cropping system I fed in the order and length (days) oat-vetch (112), wheat-trifolium plus cowpea hay (70) and teff straw plus cowpea hay (70) (T3) or forages from cropping system 2 fed in the same order and length (days) (T4). Cowpea hay and wheat middli ngs were supplemented at 1% of body weight. Maize-Lablab and oats-vetc h forages contained similar levels of CP which were higher than that i n. wheat-trifolium. The basal teff straw did not meet the calcium (Ca) and phosphrous (P) needs of the steers (TI). However, supplementation with cowpea hay satisfied all mineral needs and improved DM disappear ance (P<0.01) from nylon bags. Steers on T2 gained more (P<0.01) live weight and were more (P<0.01) efficient than steers on T4 (541 vs 373; 0.10 vs 0.08) which in turn were superior (P<0.05) to those on T3 (28 0; 0.06). Whereas, the intakes of oat-vetch were similar (3.8 vs 3.7 k g/hd/day) resulting to similar growth rate (200 vs 234 g/day) between T3 and T4, the intake of wheat-trifolium plus cowpea hay (T3) was 5% h igher than that of maize-lablab plus cowpea hay. However, the superior digestibility of maize-lablab plus cowpea hay resulted in 1.1 times i ncreased digestible organic matter intake which could explain the supe rior growth rate of T4 steers (411 vs 283). The inferior feeding value of forages from cropping system I (T3) could be attributed to leaf sh attering of the trifolium component. It was concluded that the intercr opped feeds were still deficient in CP and energy and should not be us ed as sole feed.