Organic fattening of entire male pigs from two sire lines under two feeding strategies : Part 2: Meat quality and boar taint

AbstractFattening of entire male pigs can result in boar taint and affects growing performance as well as meat and carcass traits. The objective of the present study was to test the effect of two terminal sire lines (Duroc, Du vs Piétrain, Pi) and two feeding strategies (without (-) vs with 10 % (+) raw potato starch 28 days (SD: 10.8) prior to slaughter) on meat quality parameters as well as the occurrence of boar taint in meat. Animals were reared under organic housing and feeding conditions using German Landrace*German Large White sows and nine Duroc and seven Pietrain Artificial Insemination-boars. The electrical conductivity 24 h p.m. (EC24) between the 13th and 14th rib, meat colour (L*, a, b), intramuscular fat content (IMF), and fatty acid composition of IMF, as well as the amount of skatole (SKA), indole (IND), and androstenone (AND) in the shoulder fat, were measured in a total of 280 boars (65 Du-, 73 Du+, 68 Pi-, 74 Pi+). A trained sensory panel performed an olfactory evaluation of the fat. No differences were found in terms of the physical parameters of meat quality. The content of the IMF was significantly higher in Duroc than in Piétrain offsprings. Regardless of the diet, AND was higher in Du than in Pi (920 vs 680 ng g^-1). The content of IND was similar for Du and Pi, and the use of raw potato starch had a reducing effect on IND compared to the control diet (3.6 vs 7.8 ng g^-1). The content of SKA was the highest in Pi- (94.0 ng g-¹), while its levels in Pi+, Du-, and Du+ were similarly low (38.0 ng g^-1). Concentrations of IND and SKA were generally low in the samples. Sensory evaluation of the fat samples showed no difference between the trial groups. In conclusion, the use of Piétrain as terminal sire line seems suitable to reduce the level of androstenone in boar meat. Although the use of raw potato starch reduced the amount of indole, feeding the diet containing 10 % of potato starch led to inconsistent results regarding skatole contents in Piétrain and Duroc due to a significant genotype*feeding interaction.