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

Kondreddy Eswar Reddy,Sung Dae Lee,Kyu Ree Park,Ji-Hyock Yoo,Hyun-Jung Lee,Ah Reum Son

doi:10.7717/peerj.3936

Kondreddy Eswar Reddy, Sung Dae Lee + Show 4 more

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https://doi.org/10.7717/peerj.3936

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Abstract

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 r2 (>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.

Highlights

Heavy metal poisoning in swine feeds is one of the problems in the swine industry
Swine feeds can be contaminated through mineral premix and ingredients originated from soil containing high concentration of heavy metals (Obeid et al, 2014; MacLachlan et al, 2015)
The heavy metals can be accumulated in soft tissues, bones, and hair of pigs and accumulated heavy metals in edible tissues of pigs can be transferred to human and other animals through the food chain (Doyle & Spaulding, 1978; Grybauskait, Laurinavicien & Cikockait, 2014; Obeid et al, 2014)

Summary

Introduction

Heavy metal poisoning in swine feeds is one of the problems in the swine industry. Swine feeds can be contaminated through mineral premix and ingredients originated from soil containing high concentration of heavy metals (Obeid et al, 2014; MacLachlan et al, 2015). The heavy metal fed to pigs can depress growth performance and cause clinical disorders. Domestic animals are potentially exposed to lead (Pb) via contaminated mineral premix, and contaminated feed ingredients and soil (MacLachlan et al, 2015). The Pb can be absorbed through the gastrointestinal tract, respiratory tract, and skin, and can be accumulated in various animal tissues. Absorbed Pb is excreted very slowly from the body (Papanikolaou et al, 2005)

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