The problem of gizzard erosion in poultry has been linked with the presence in some fishmeal samples of a contaminant, gizzerosine, which stimulates the secretion of acid by the proventriculus. In 1985, a severe outbreak of gizzard erosion in a broiler unit in Devon was associated with the inclusion of Chilean fishmeal at 90g/kg. When the inclusion rate was reduced to 30g/kg the symptoms disappeared. This experiment used fishmeal from the same batch as that which had apparently caused gizzard erosion, and the same rates of inclusion, to examine the potential of NaHCO. to buffer the effects of increased acid secretion.