Loss of carcass weight, liver weight and liver glycogen, and the effects on muscle glycogen and ultimate pH in pigs fasted pre‐slaughter

Abstract

AbstractPigs (50–65 kg) were last fed 24, 16 or 1 h before transport to slaughter. The journey lasted 1 h and on arrival they were killed after either 1 h or overnight lairage. Although not statistically significant, carcass weight was greater in groups fasted least and those killed after 1 h lairage and these differences were reflected in significantly higher killing‐out percentages in these groups. Relatively rapid loss of both live and carcass weight commenced after about 18 h after the last meal, and it was concluded that, to prevent economically important losses, total time from last feed to actual slaughter, including transport and lairage, should not exceed this length of time. The rate of liveweight loss was approximately 0.21 % h−1 and the loss in carcass weight was 0.13% h−1 of fast. Longer lengths of fast significantly reduced liver weight, liver and muscle glycogen and raised muscle ultimate pH. Transport resulted in a large rate of loss in liveweight in proportion to that caused by fasting alone. Backfat thickness was not affected by any of the treatments.