Effects of graded concentrations of supplemental lead on lead concentrations in tissues of pigs and prediction equations for estimating dietary lead intake

The objectives of this experiment were to determine the effects of graded dietary lead (Pb) concentrations on body weight and Pb concentrations in blood, hair, soft tissues, and urine from pigs and to generate equations for estimating daily Pb intake. Sixteen barrows with initial body weight 36.3 kg (standard deviation = 2.3) were allotted to four dietary treatments that consisted of graded supplemental Pb concentrations (0, 10, 25, and 250 mg/kg of diet). Daily feed allowances for each pig were 1 kg for first two weeks and 2 kg for last two weeks. The hair and blood of pigs were collected on d 14 and 28. At the end of experiment, the pigs were euthanized, and the liver, kidneys, muscle, and urine samples were collected. The prediction equations for estimating daily Pb intake of pigs were generated using Pb concentration of blood, hair, tissues, or urine as an independent variable. The Pb concentrations in the blood, hair, liver, kidneys, muscle, and urine linearly increased (P < 0.01) with increasing dietary Pb concentrations. There were quadratic effects (P < 0.05) of increasing dietary Pb concentration on Pb concentrations in the blood, hair, and muscle. There were highly positive correlations between dietary Pb concentration and Pb concentrations in the blood, hair, liver, kidneys, muscle, and urine (r > 0.83; P < 0.01). The equations were significant (P < 0.01) and showed high r(2) (>0.83), except the equation using Pb concentration in the muscle as an independent variable. In conclusion, the dietary Pb concentration was highly correlated with Pb concentrations in the blood, hair, soft tissues, and urine of pigs. The total dietary Pb intake can be estimated from the Pb concentrations in the blood, hair, soft tissues, or urine for pigs.