1. Renal function was studied in laying hens which had been fed on diets containing 0 (control), 10 or 20% dried poultry manure (DPM) for one year.
2. Birds fed on 20% DPM showed increased rates of effective renal plasma flow and increased renal tubular secretion of urate during the infusion of large amounts of urate.
3. Renal hypertrophy was not detected in any group.