The coordination of dietary valine and isoleucine on water holding capacity, pH value and protein solubility of fresh meat in finishing pigs.

To investigate coordination of dietary levels of valine (Val) and isoleucine (Ile) on carcass traits and meat quality in pigs, 72 of 73.8 ± 1.6 kg crossbred barrows were randomly divided into a 2 (0.31% vs. 0.65% standard ileum digestible (SID) Val) × 2 (0.25% vs. 0.53% SID Ile) factorial arrangement. As a result, high dietary valine decreased myosin heavy-chain (MyHC)-I mRNA expression, pH24 h value, bound water amount (T21 peak area ratio), sarcoplasmic protein solubility and water holding capacity (WHC) of meat (P < .05). Meanwhile, high dietary isoleucine increased pH24 h value, sarcomere length (P < .05) and tend to decrease drip loss (P = .07). The significant interactions between valine and isoleucine were observed on backfat thickness, water distribution forms and myofibrillar protein solubility (P < .05) of pork. High valine diets undermined WHC of meat probably through decreasing pH24 h value and sarcoplasmic protein solubility considering their significant correlations with drip loss.