Time-Resolved Fluoroimmunoassay for the Measurement of Androstenone in Porcine Serum and Fat Samples

A simple competitive time-resolved fluoroimmunoassay was developed for the analysis of the boar taint steroid 5α-androst-16-en-3-one in serum and fat samples. Sensitivities of 30 ng/g and 0.8 ng/mL were obtained for fat and serum measurements, and the assays had mean recoveries of 97% and 103%, respectively. The average coefficients for intra- and interassay variation in fat analysis were 6.0%/8.9%, and in serum measurements 5.4%/8.1%, respectively. Boar fat samples contained androstenone in the range of 130−11570 ng/g ( n = 106), and in the 108 kg boar group, 58% of samples exhibited fat androstenone levels above 500 ng/g. The serum androstenone concentrations in boars ranged from 1.5 to 237.3 ng/mL ( n = 154), but were almost exclusively below the assay range in barrows ( n = 124) and gilts ( n = 83). A significant ( p < 0.0001) correlation was observed between boar serum and fat androstenone concentrations ( r = 0.89, n = 102). A direct serum analysis seems to give a reliable indication of the androstenone level in fat and could be useful in the routine screening for boar taint. Keywords: Androstenone; boar taint; pigs; time-resolved fluoroimmunoassay