This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPT AbstractThis study evaluated the effect of animal temperament measured using flight speed (FS) on plasma lactate, muscle glycogen and lactate concentrations at slaughter plus ultimate pH in 648 lot finished cattle of mixed breed and sex. Muscle samples were collected at slaughter from the m. semimembranosus (SM), m. semitendinosus (ST) and m. longissimus thoracis (LT) for analysis of glycogen and lactate concentration. Blood was collected after exsanguination and analysed for plasma lactate concentration and ultimate pH of the LT was measured. FS had no effect on muscle glycogen concentration in any muscle or ultimate pH of the LT (P>0.05). As FS increased from 1 to 5 m/s, plasma and muscle lactate concentration increased by 54% and 11.4% respectively (P<0.01). The mechanisms through which animal temperament contributes to variation in glycogen metabolism remain unclear. A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPTThe risk of dark cutting was not impacted by temperament, indicating that other production and genetic factors have a greater impact on the incidence of dark cutting.Keywords: Ultimate pH, glycogenolysis, muscle contraction, dark cutting, catecholamines, stress A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPT AbstractThis study evaluated the effect of animal temperament measured using flight speed (FS) on