Abstract 81

D'Mello,-JPF; Acamovic,-T; Walker,-AG

Department of Agricultural Biochemistry, Edinburgh School of Agriculture, West Mains Road, Edinburgh EH9 3JG, UK.

Tropical-Agriculture. 1989, 66: 3, 201-205; 18 ref.

Groups of day-old Marshall B1 chickens were given basal diets without (controls) or with autoclaved jack beans (Canavalia ensiformis) (AJB) 140 g/kg diet. Jack beans were soaked at 40 ø C for 24 h then autoclaved at 135 ø for 5 min in experiment 1, and at 121 ø for 60 min in experiment 2. Although brief autoclaving of beans permitted survival of all chickens, more prolonged autoclaving improved growth performance and efficiencies of feed and nitrogen utilization. Irrespective of autoclaving treatments, chickens fed on the AJB basal diet grew at slower rates, consumed less DM and utilized feed less efficiently than controls. In experiment 1, arginine or arginine + lysine additions to the AJB basal diet were equally effective in improving growth rates and DM intakes. Serum canavanine concentrations were unaffected by amino acid supplementation of the AJB basal diet. Urea-N excretion as a proportion of total N excretion was higher in chickens fed on the AJB basal diet or AJB basal + arginine than in those fed on the control diet. In experiment 2, supplements of ornithine, glycine, arginine and lysine, in different combinations, did not improve growth rates, DM intakes or efficiencies of feed and N utilization of chickens fed on the AJB basal diet. In both experiments, AJB diets supplemented with amino acids had poorer growth performance and feed utilization.