EFFECT OF BREED ON THE MUSCLE GLYCOGEN-CONTENT AND DARK CUTTING INCIDENCE IN STRESSED YOUNG BULLS

Observations have shown relevant differences in the behaviour of Blown Swiss bulls and Pirenaico bulls. Because temperament is involved in t he development of dark cutting beef (DC), the aim of this study was to investigate the influence of breed on muscle glycogen content and on the incidence of DC condition. Twenty-four Brown Swiss bulls and 24 Pi renaico bulls were used The animals were divided into a stressed group (S) and a control group (C). In group S, bulls were mixed with unfami liar animals overnight before slaughter. In group C, bulls were slaugh tered immediately after arrival at the abattoir. The results show that the glycogen concentrations in m. longissimus dorsi and m. sternomand ibularis from unstressed animals were similar in both the Brown Swiss and the Pirenaico breeds. The muscle glycogen concentration was deplet ed in all stressed bulls, nevertheless some low concentrations were in sufficient to adversely affect the meat ultimate pH value. Finally, th ere was no influence of breed on the incidence of the dark cutting con dition. Copyright (C) 1996 Elsevier Science Ltd