This study investigates the combined effect of immunocastration, dietary protein level (low, medium or high) and ractopamine hydrochloride supplementation (0 or 10 mg/kg) on the adipose concentrations of androstenone, skatole and indole in pigs, and explores whether body mass, carcass fatness or testicular parameters may be indicators of boar taint in these carcasses. Immunocastration was successful in decreasing testicle functioning, and adipose androstenone and skatole concentrations, in all individuals. Immunocastration decreased testicle weight and length, seminiferous tubule circumference and epithelium thickness. Testicle tissue from immunocastrates was also paler, and less red in color, in comparison to non-castrated controls. Dietary protein level and ractopamine hydrochloride supplementation had no influence on the adipose concentration of androstenone, skatole and indole. Testicle size and color were moderate to strong indicators of androstenone and skatole concentrations in the carcasses, and thus vaccination success. Immunocastration together with the adjustment of dietary protein and ractopamine hydrochloride supplementation, is successful in preventing boar taint while maintaining growth performance.

Center for Nutrition and Food Sciences Queensland Alliance for Agriculture and Food Innovation The University of Queensland Health and Food Sciences Precinct 39 Kessels Rd Coopers Plains 4108 Australia

Department of Animal Science and Food Processing Faculty of Tropical AgriSciences Czech University of Life Sciences Prague Kamýcká 129 16500 Prague Suchdol Czech Republic

Department of Animal Sciences University of Stellenbosch Private Bag X1 Matieland Stellenbosch 7602 South Africa

School of Agricultural Earth and Environmental Sciences University of KwaZulu Natal Scottsville 3209 South Africa

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