A complex polysaccharide, GBA, shown in other applications to have adjuvant and nonspecific immunoenhancing properties, is obtained from a bacterium of the genus CvtoDhagv. Preliminary results indicate that oral administration of GBA to hatchling chickens increases their growth rate. Phase I of the proposed study will establish the following: the effects of GBA on growth rate and body composition (protein, fat, water, etc.); the effects of different doses; the effects of different administration regimes (single dose, variation of the administration schedule for repeated doses); the effects of GBA compared to those of a commonly used antibacterial feed additive, virginiamycin; the effects of a chemically modified derivative of GBA and a form of the polysaccharide bound to the pigment with which it is eomplexed when produced by the bacterium; the acute toxic effects and body clearance of GBA; and that GBA is not bacteriocidal for a collection of bacterial species, i.e. that GBA is not an antibiotic. Phase II of the study will be devoted to exploring the exact mode of action of GBA.Applications:The proposed study will establish the relative value of GBA as a growth enhancer for chickens, as well as the optimal feeding regimen and dosage. The study will give an indication of whether GBA stimulates immune processes and whether it affects digestive processes or the control and composition of the microflora of the gut. The study will also determine the commercial potential of GBA as a feed additive, alone or in combination with antibiotics presently in use.
