Nn. Umunna et al., STRATEGIC SUPPLEMENTATION OF CROSSBRED STEERS FED FORAGES FROM CEREAL-LEGUME CROPPING SYSTEMS WITH COWPEA HAY, Journal of Applied Animal Research, 11(2), 1997, pp. 169-182
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.