Male pig pubertal development and risk of boar taint

International audience

English. Male pigs are commonly surgically castrated, without anaesthesia, to avoid a meat quality defect called boar taint, partially due to accumulation of androstenone in fat. Androstenone is a steroid produced by the testes. To decrease boar taint without using castration, a selection against androstenone should be considered. The purpose of this study is to estimate the relationships between androstenone and reproductive traits in boars. In this study we collected 34 traits for 36 Duroc boars, 40 French Landrace boars and 38 Pietrain Axiom NN boars. Characteristics of the semen (number of spermatozoids, mobility, motility, volume, concentration, duration of ejaculation and viability), libido indicators (number of training sessions before the first successful collection and percentage of later refusals), plasma testosterone and oestradiol levels, backfat levels of androstenone, skatole and indole at 180 and 280 day old, the age at 100 kg, the weight of genital tract and indicators of animal behaviour, health and welfare (human-animal relationship test, tears, health and leg scores). We estimated a high Pearson correlation between plasma oestradiol and androstenone in backfat at around 180 days of age (0.57). This confirms that plasma oestradiol can be used as a proxy for androstenone at the standard slaughter age. From Principal Component Analyses, it seems that fat androstenone at 180 days of age is independent from health score, behaviour toward human, libido and semen characteristics. These results suggest that a selection for lower androstenone in fat or plasma oestradiol in pigs at a standard slaughter age would have very-limited impact on libido or semen production capacities of mature boars.