Effects of slaughter weight and sex on intramuscular colour defects in pork ham

This study investigated the effects of slaughter weight (SW; 125 vs. 150 kg) and sex (barrows vs. gilts) on ham chilling rate, ham composition, colour characteristics, and defect prevalence in fresh ham centre slices. A total of 312 pigs (barrows, n = 155; gilts, n = 157) were used. Postmortem subjective and objective (Red, Green, Blue) colour measurements were conducted on individual ham muscles (biceps femoris, BF; semimembranosus, SM; semitendinosus, ST). Heavy gilts exhibited the slowest chilling rate (-2.37 °C/h), whereas light gilts had the fastest rate (-2.45 °C/h; P ≤ 0.030), with barrows showing intermediate values. Significant SW × Sex interactions were observed for ham fat (P = 0.02) and lean percentages (P = 0.03), but not for other traits (P > 0.05). Trends were noted for ST moisture (P = 0.05) and subjective colour score difference (ΔSC) in ST (P = 0.08). Increasing SW increased objective colour differences (ΔR, ΔG, ΔB) between pale and normal regions in BF and ST (P < 0.001), but not in the SM (P ≥ 0.61). Tendencies for increased ΔSC were observed in BF and SM (P ≤ 0.07), whereas no differences were detected in ST (P = 0.27). Slaughter weight was not associated with defect prevalence (P ≥ 0.08). In conclusion, increasing SW to 150 kg slows carcass chilling and alters ham composition but does not substantially increase the incidence of intramuscular colour defects. These findings suggest that increasing SW to 150 kg does not adversely affect ham colour uniformity under the conditions evaluated.