Lead toxicity and metabolism from lead sulfate fed to Holstein calves

Sixteen Holstein intact male calves averaging 85 kg and 74 days of age were assigned randomly to four dietary lead treatments according to body weight. They were fed for ad libitum consumption a control diet containing no added lead or the control diet supplemented with 500, 1500, or 4500 ppm lead as lead sulfate. One calf fed 1500 ppm lead and all four calves fed 4500 ppm lead died within 6 to 10 days after initiation of treatments. Death was sudden with few or no clinical signs prior to death. Those clinical signs that did appear included muscular tremors, gnashing of teeth, bellowing, and convulsions. Four control, four 500 ppm lead, and two 1500 ppm lead-fed calves survived the 7-wk experimental period. Feed consumption, body weight changes, glutamic oxaloacetic transminase and alkaline phosphatase activity in blood plasma, and hemoglobin were not affected significantly by lead treatments. Packed cell volume in calves fed 500 and 1500 ppm added lead was reduced. Lead concentrations in blood, kidney, liver, bone, brain, and muscle were elevated in lead supplemented calves above those of controls. The highest concentrations of lead were in kidney and liver.