Bovine muscle glycogen concentration in relation to finishing diet, slaughter and ultimate pH

The aim of this study was to investigate the effects of a high-energy diet provided for a rather short time prior to transportation to slaughter on muscle glycogen concentration on farm, after transportation and after refrigeration of the carcasses. The experiment involved 60 Ayrshire bulls which were fed either a low energy diet of 100% grass silage or a compound feed based diet providing 10.8 and 12.9 MJ of metabolizable energy per kg of dry matter, respectively. Identical setup of 30 bulls was carried out in spring and in summer. Three muscle samples were obtained from the longissimus dorsi and gluteus medius muscles: a biopsy prior to initiation of experimental feeding (B1); another biopsy after 14 days on diet (B2); a post mortem sample at 48 h after slaughter (3) (also M. semimembranosus). Initial resting muscle glycogen concentration affected the responsiveness of glycogen to diet. The more glycogen there was initially the less glycogen increased ( r=−0.678, p