Effects of Days on Concentrate Feed and Postmortem Aging on Carcass and Palatability Characteristics of Selected Muscles from Cull Beef Cows1

Twenty-four beef cows were selected to examine the effects of concentrate feeding on performance and to examine the effects of concentrate feeding and postmortem aging (10 or 20 d) on the triceps brachii lateral and long heads, infraspinatus, longissimus lumborum, psoas major, gluteus medius, tensor fascia latae, rectus femoris, and vastus lateralis. Cows were randomly assigned to a concentrate diet for 0, 42, or 84 d. Carcass characteristics were measured and Warner-Bratzler shear force, sensory evaluation, and collagen analyses were performed on selected muscles. Cow BW, ADG, and BCS increased (P 0.05) sensory off-flavor detection. Concentrate feeding of cull cows for 84 d improved carcass characteristics and the tenderness of several muscles. These muscles may be aged for 20 d postmortem to achieve maximal tenderness without detrimental off-flavor production.