Effect of dietary lead on performance, tissue mineral composition and lead absorption in sheep.

Twenty wether lambs were individually fed for 84 days to study the effect of dietary lead on performance and mineral composit ion of selected tissues. The treatments included O, 10, 100, 500 and 1,000 ppm supplemental lead as lead acetate added to a practical diet. Increased dietary lead did not affect feed consumption, weight gain or feed conversion ratio. Hemoglobin, hematocri t and blood lead were not affected by dietary treatments. Lead concentrations were higher (P<.01) in liver, bone, brain and spleen when 500 and 1,000 ppm dietary lead was fed. High dietary lead also resulted in higher (P<.05) lead concentrations in kidney, heart and muscle. As dietary lead increased, zinc levels in heart and brain increased (P<.01) and iron levels in the brain decreased (P<.01). In a second study, six sheep each were assigned to diets containing either 50 or 1,000 ppm supplemental lead, respectively, to determine the effect of dietary lead on nutrient digestibility, nitrogen and lead balance. Supplemental lead did not affect nutrient digestibility or nitrogen balance. More lead was absorbed and retained with the greater intake but the percentage of apparent absorption and net retention of lead was not significantly different among treatments. (