Abstract

Low ultimate-pH of beef is desirable because it enhances shelf life, colour and tenderness. Pre-slaughter stress is thought to deplete muscle glycogen and in extreme cases lead to higher ultimate pH of beef. Seventeen-month-old steers were allocated to three treatments (n=15): Control (C, grazing on pasture), Yarded (Y, held for 24 hours in cattle yards) and Yarded plus Transported (YT, as for Y but also trucked for 4 hours during the 24-hour yarding period). The Y and YT animals lost weight (average 25.5 kg) during time off pasture. Plasma glucose and lactate did not differ across treatments. Plasma cortisol and creatine kinase concentrations were increased by YT and plasma non-esterified fatty acids concentration by both Y and YT. Despite these indicators of occurrence of mild stress, especially in YT, muscle (longissimus dorsi) glycogen concentration was not influenced by treatments. Results suggest that increased emphasis on improved animal handling during yarding and trucking of cattle is unlikely to markedly lower the incidence of high-pH beef.

MG, Lambert, TW Knight, GP Cosgrove, AF Death, and CB Anderson

Proceedings of the New Zealand Society of Animal Production, Volume 60, Hamilton, 124-125, 2000