Influence of selection for improved growth rate on pork quality

Abstract

Variation in pork quality attributes like water-holding capacity and tenderness continues to reduce value of fresh pork. It is hypothesized that selection for improved growth rate has the potential to result in a loss of desirable fresh pork quality. The objective of this study was to investigate the contribution of selection for improved growth rate to variation in fresh pork quality. A pig population derived from the cross between a commercial line of Duroc sires and white line dams was subdivided according to the sires’ estimated breeding value (EBV) for age at 125 kg. Two slaughter groups were established. The first slaughter group included the most rapid growth High (Fast Growth) EBV pigs (n=48; 150 d at 125 kg) and a reference group that included Low (Slow Growth) EBV pigs (n=8; 160 d at 125 kg) and High EBV pigs (n=8; 160 d at 125 kg). The second slaughter group consisted of the slowest growing Low EBV pigs (n=48; 180 d at 125 kg) and a reference group that included Low EBV pigs (n=8; 174 d at 125 kg) and High EBV pigs (n=8; 169 d at 125 kg). Each group was harvested at a commercial facility. Loin pH and temperature decline was monitored on each carcass. Fresh pork quality characteristics and water-holding capacity was monitored at 2 d postmortem. Sensory characteristics (juiciness, tenderness, chewiness, flavor, and off-flavor) and star probe texture were measured 10 d postmortem. Pigs in High