The Effect of Feed Withdrawal Duration on the Responsiveness of Broiler Pectoralis to Rigor Mortis Acceleration

This experiment was conducted to examine the effect of the duration of preslaughter feed withdrawal on the responsiveness of chicken muscle tissue to rigor mortis acceleration. Rigor mortis was accelerated by combining electrical stimulation and high temperature conditioning immediately post-mortem. At 1 h post-mortem, one breast fillet from each carcass was removed, frozen, and analyzed for metabolic and structural characteristics. The other fillet was excised, aged for 23 h, cooked, and sheared. As duration of feed withdrawal increased, muscle glycogen decreased. Shear value and pH decreases were most pronounced after 5 h of feed withdrawal. The feed withdrawal period did not affect R value, fragmentation index, or sarcomere length. Rigor mortis acceleration resulted in longer sarcomeres and increases in R value and fragmentation index.