The effect of gender of finishing pigs slaughtered at 110 kilograms on performance, and carcass and meat quality

Abstract

Twenty-four crossbred pigs (Large White × Landrace × Segher) were divided into three equal groups of boars, barrows and gilts. Prior to slaughter, they were raised from 30 kg to 110 kg. under controlled conditions. Gender had no significant effect concerning total weight gain, average daily gains, feed conversion ratio, and production costs. Backfat thickness of boars was lower (p<0.05) than that found in barrows and gilts (2.27 vs. 2.96 and 2.73 cm, respectively). In other carcass quality traits, such as dressing percentage, carcass length, loin eye area and lean percentage, there were no significant differences among groups. Lean meat percentage was lower (p<0.05) in barrows, than in boars and gilts. Applying Thai cutting style, there was a higher (p<0.05) lean meat percentage in boars than in barrows while fat percentage was lower (p<0.05) in boars compared to the barrows (8.2 vs. 11.0 %, respectively). Meat pH was found to not be significantly different across groups. However, boars tended to have a comparatively faster rate of pH decline. Therefore, their carcasses were more susceptible to PSE. Color (L*, a*, b*), drip loss and thawing loss differed among the three groups. Boiling loss of boar and gilt meat was larger (p<0.001) than that of barrow meat (22.1 and 23.1 vs. 16.2%, respectively). However, intramuscular fat content was higher (p<0.05) in the barrows than in boars and gilts, while the latter groups did not differ much. Although not obvious from flavor scores, boar meat showed the overall lowest sensory acceptance. This was mainly caused by reduced (p<0.05) tenderness scoring, which was partially confirmed by shear force measurements, the lower juiciness impression, and less obviously by the highest (p<0.001) plasma testosterone level (278 vs 0.09 and 0.02 pg/ml in boars vs. barrows and gilts), probably associated with high levels of androstenone, and backfat skatole concentrations. Backfat contents of unsaturated fatty acids, among them the dietetically undesired arachidonic acid, tended to be slightly higher in boars than in barrows and gilts, and this was associated with a clearly (p<0.05) softer fat and a higher inclination for oxidation as determined in the backfat. Overall, this suggests that boar meat has a slight advantage in carcass quality but is clearly inferior in quality compared to meat from barrows and gilts even in the absence of noticeable boar taint.