Determination of Tiamulin Concentration in Sow Milk and in Sera of Suckling Piglets

Abstract

Although modern analytical methods developed for monitoring antibiotics in severalbiological matrices are easily available, none of them have been applied to evaluate the transferof tiamulin into sow milk. Therefore, this work was intended to analyse the concentrations oftiamulin in milk samples collected from lactating sows during and after a treatment consisting ofthree consecutive intramuscular applications of the antibiotic. The second aim of this investigationwas to determine tiamulin concentrations in serum samples obtained from suckling piglets ingestingmilk contaminated with the compound. Ultra-high-performance liquid chromatography coupledwith tandem mass spectrometry (UHPLC-MS/MS) was used to quantify the analyte in both matrices.Our investigation proved tiamulin was transmitted into the milk of lactating sows. The meanconcentration of the antibiotic among samples collected 3 h after administration was 1043 μg/L. Themean level of tiamulin on days 1 and 2 was 876 μg/L and 902 μg/L, respectively. The highest meanconcentration of the antibiotic (1061 μg/L) was observed in samples collected on day 3. The meanconcentration of the antibiotic in serum samples collected from 3-day-old piglets was 22.2 μg/L.The association between their body weight and serum tiamulin concentration was not statisticallysignificant (p = 0.456)