Feeding and aging effects on carcass composition, fatty acid profiles and sensory attributes of muscles from cull cow carcasses.

摘要

By feeding cull cows, it may be possible to increase the utilization and value of the carcass. Sensory data from the current study showed that commercially identified beef non-fed (B-NF), beef fed (B-F), dairy non-fed (D-NF), and dairy fed (D-F) cows were less tender (P 0.05) than USDA Select grade A-maturity beef carcasses (SEL), with B-NF the least tender overall. Instrumental tenderness measurements revealed B-NF as the least tender (P 0.05) and SEL as the most tender (P 0.05). All cow groups exhibited increased (P 0.05) beef flavor intensity ratings and increased (P 0.05) off-flavor than SEL. Psoas major was the most tender muscle researched, with the Teres major and the Infraspinatus second and third. However, the Psoas major also had one of the highest levels of off-flavor detection, along with the Gluteus medius and Triceps brachii-lateral head. Sensory off-flavor was not related (P > 0.05) to fatty acid profiles in any group.; When cull beef cows were fed a known concentrate diet for 84 days, live performance traits and carcass characteristics improved (P 0.05) when compared to cull cows that were not fed prior to slaughter. In addition, lean color became a brighter more cherry red (P 0.05) and fat color became whiter (P 0.05). Percent and total (mg/g) soluble collagen increased (P 0.05) and four of the nine muscles examined had lower Warner-Bratzler shear force (WBS) scores after 84 days on feed. Sensory analysis showed that steaks from cows fed for 84 days were more tender (P 0.05) and had less (P 0.05) detectable off-flavor than steaks from cull cow carcasses that were not fed. Postmortem aging 20 days increased sensory tenderness and decreased WBS in cow steaks compared to steaks aged 10 days postmortem. Concentrate feeding of cows improved sensory off-flavor scores: however, the fatty acid profiles of steaks from these cows were not related (P > 0.05) to off flavor score. Short-term feeding of cows for 84 days will substantially improve carcass characteristics and muscle quality, making them more acceptable for utilization in the beef industry.