Toxicity of dietary lead in young cockerels.

Day-old cockerels received 1850 ppm dietary lead for 4 wks. Blood delta-aminolevulinic acid dehydratase (ALAD) activity was reduced to 1.6% of control activity by the end of the study. Hemoglobin concentration (Hb) in lead-exposed cockerels was significantly less than that of controls at 7, 14, and 28 days, and packed cell volume (PCV) was significantly reduced at 14 days. Blood lead residues reached 832 micrograms/dl in exposed cockerels; kidney residues were about three times liver residues. At the termination of the study mean body weight of lead-exposed birds was 47% of controls.