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ARS Home » Plains Area » Lubbock, Texas » Cropping Systems Research Laboratory » Livestock Issues Research » Research » Publications at this Location » Publication #386516
Research Project: Nutritional Intervention and Management Strategies to Reduce Stress and Improve Health and Well-being in Cattle and Swine

Location: Livestock Issues Research

Title: Effects of pre-mortem stress on protein expression, steak color, oxidation, and myofibrillar fragmentation index in the longissimus lumborum

Author
item BRIGGS, REGANNE - Utah State University
item LEGAKO, JERRAD - Texas Tech University
item Broadway, Paul
item Carroll, Jeffery - Jeff Carroll
item Sanchez, Nicole
item INECK, NIKOLE - Utah State University
item SMITH, ZACHARY - South Dakota State University
item RAMANATHAN, RANJITH - Oklahoma State University
item THORNTON, KARA - Utah State University

Submitted to: Meat Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/15/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary: Tenderness is one of the most important meat characteristics according to consumers. Despite similar production practices, large variations exist in tenderness and the stability of flavor and color of meat from beef cattle. Therefore, scientists from ARS' Livestock Issues Research Unit, Utah State University, South Dakota State University and Oklahoma State University conducted a study to determine how stress prior to harvest impacts meat tenderness and color. Specifically, the scientists looked at how stress at 2, 12, 24 and 48 hours before harvest impacted meat tenderness and color in dairy calves. The results revealed that time of harvest and the stress hormone response following a stressful event affects meat tenderness and color. This information will be of interest to beef cattle producers, feedlot managers, managers of harvest facilities, and scientists working in the field of meat science.

Technical Abstract: This study aimed to determine effects of pre-mortem stress in the longissimus lumborum (LL) following harvest. Forty Holstein steers underwent an adrenocorticotropic hormone challenge. Samples were collected from the LL prior to the challenge, at different harvest times (2, 12, 24 and 48 h post-challenge), and after 14 d aging. Expression of small heat shock proteins (HSPß1, P-HSPß1, HSPß5), DJ-1 and troponin were analyzed. Steak color and myofibrillar fragmentation index (MFI) were analyzed in 14 d aged samples. Despite randomization, cortisol response was different (P < 0.001) among steers assigned to different harvest times. As such, data were also analyzed by cortisol response. Harvest time affected expression of P-HSPß1 (P < 0.005), DJ-1 (P < 0.04), and troponin (P < 0.02). Harvest time and cortisol response impacted steak color (P < 0.05). Harvest time also changed (P = 0.04) MFI. These data demonstrate protein expression, color, and MFI of the LL may be related to when harvest occurs following pre-mortem stress.