LAUSR

BACKGROUND Animal handling practices are one of the factors majorly affecting animal metabolism prior to slaughter. This phenomenon increases the occurrence of meat quality defects such as dark cutting-beef, causing high economical losses in the meat industry. Under this framework, the assessment of apoptosis onset in post mortem muscle was proposed as a novel approach to reveal biochemical characteristics in several Spanish bovine breeds (Asturiana de los Valles, Retinta and Rubia Gallega) managed under different production systems (intensive vs semi-extensive) and transport/lairage conditions (mixing vs not mixing with unfamiliar animals). To do so, the activities of initiator caspase 9 and executioner caspases 3/7 were determined in Longissimus thoracis et lumborum muscle at three early post mortem times (2, 8 and 24 h). RESULTS Breed effect and transport/lairage conditions were the most relevant factors that influenced both caspase activities over post mortem time, showing Rubia Gallega breed a completely different behaviour compared to Asturiana de los Valles and Retinta breeds. Moreover, it is postulated that apoptosis cascade is initiated via the activation of caspase 9 under hypoxic or metabolic stress followed by the activation of executioner caspase 3/7. CONCLUSIONS Assessment of apoptosis on post mortem muscle can be a novel approach to study the influence of animal handling on muscle metabolism and post mortem cell death and its consequences on meat quality traits. This article is protected by copyright. All rights reserved.