EFFECTS OF EXOGENOUS PORCINE SOMATOTROPIN ON PERFORMANCE, TESTICULAR-STEROID PRODUCTION AND FAT LEVELS OF BOAR-TAINT-RELATED COMPOUNDS IN YOUNG BOARS

Large White x Pietrain boars were administered 0 or 5 mg recombinant porcine somatotropin (pST) daily between 68 and 105 kg live weight in an investigation of the effects of pST treatment on growth performance, carcass traits, genital-tract development, steroid-hormone synthesis, and fat skatole and androstenone levels in young male pigs. Growth rate was not affected by pST treatment, daily feed intake was decreased 9% (P < 0.05), and feed efficiency was improved 7% (P < 0.01). Muscle content of the carcass was increased from 57.7% to 59.7%, and fat content was reduced from 18.8% to 15.7% (P < 0.001). Genital-tract development, testicular androgen and 16-androstene biosynthesis rates and skatole levels in fat were not affected by pST treatment. Androstenone levels in fat were reduced from 0.66 mug g-1 in control animals to 0.35 mug g-1 in pST-treated animals (P < 0.001). The results of the present experiment indicate that pST treatment of boars of a lean genotype significantly improves the performance of the animals and may contribute to a reduction in the incidence of boar taint.