Relationship between sperm production and boar taint risk of purebred or crossbred entire offspring

This study focuses on 100 boars from three Pietrain varieties: 74 V1, 10 V2 and 16 V3. On average, data were recorded on 90 ejaculates collected in artificial insemination centers and boar taint measured on 15.4 entire male offspring, half purebred and half Pietrain × Large-White type. Offspring were reared at INRA UETP (Le Rheu, France) up to 110 kg. Boar taint risk was assessed by androstenone and skatole measurements in fat collected at the slaughterhouse. Sperm production data were corrected for the production site, the age and the collection frequency using a generalized linear mixed model to estimate an average sperm production count per boar and ejaculate. Boar taint odor risk was on the whole low in the tested population. Considering the three Pietrain varieties altogether, boars with the highest sperm production had a lower proportion of offspring without risk of odor compared to boars with low sperm production: the boars ranked in the top quartile of sperm production had 14% less offspring without odor (i.e. androstenone <1.0 μg/g and skatole <0.2 μg/g) compared to the boars in the bottom quartile (P<0.05). The sperm production of the sires of pigs with high androstenone content in fat was on average higher than that of the sires of pigs with low androstenone content: 95.3 and 86.8 billion spermatozoa per ejaculate for the sires of offspring with more than 3.0 μg/g of androstenone and non-detectable androstenone level, respectively (P<0.05). Differences were more pronounced on crossbred offspring than on purebred ones. With V1 sires alone, differences were smaller but still significant. As a conclusion, selection against boar taint might negatively impact semen production if reproduction traits are not included in the breeding goal.