EFFECT OF PRESLAUGHTER HANDLING ON MUSCLE GLYCOGEN LEVEL AND SELECTEDMEAT QUALITY TRAITS IN BEEF

The ante-mortem and post-mortem glycogen levels in bull muscle were st udied to determine their influence on the ultimate pH, cooking loss an d shear force. Forty-three bulls (13 Holstein, 12 crosses Holstein x B elgium blue, 9 Slovak Pied and 9 crosses Slovak Pinzgauer x Piemontese ) were tied, housed and divided in control (A, n = 30) and stressed (B , n = 13) groups before slaughter. At the institute abattoir, the grou p B animals were mixed and kept overnight. In group A, bulls were slau ghtered immediately after arrival at the abattoir. The following value s of muscle were determined: (1) glycogen ante mortem from m. semitend inosus (ST) (biopsy technique, Biotech Nitra), (2) glycogen post morte m (1 hr, 3 hr, 48 hr) from longissimus dorsi muscle (LD), (3) ultimate pH, cooking loss and shear force 48 h post mortem. The results show t hat the glycogen concentrations ante mortem (ST) and 1 hr post mortem (LD) from unstressed animals were similar (p > 0.05). The ante-mortem and post-mortem (1 hr, 3 hr) muscle glycogen concentration were deplet ed (p < 0.01) in all stressed bulls. Differences between stressed and unstressed animals (p < 0.01) were found in ultimate pH, cooking loss and in shear force (p < 0.05). Significant correlations (p < 0.01) bet ween ante-mortem (ST) and post-mortem (LD, 1 hr, 3 hr) muscle glycogen and ultimate pH and cooking loss supported the possibility of using a n efficient biopsy technique in combination with a simple method of gl ycogen estimation (iodide method) to predict metabolic exhaustion (gly cogen depletion) and/or dark cutting condition of bulls. (C) 1998 Else vier Science Ltd. All rights reserved.