Bacon yield from fasted pigs

Abstract

Commercial crossbred pigs weighing about 80 kg and comprising equal numbers of females (gilts) and castrated males (castrates) were killed at a bacon factory 4 h (controls), 24 h or 48 h after food withdrawal. The carcasses from pigs fasted 24 h were on average 1-4 kg lighter, and those from pigs fasted 48 h, 2-9 kg lighter, than those of the control group. Fasting also reduced liver weight by about 0-3 kg but had no significant effect on backfat thickness or mean initial or ultimate pH in the muscles. Carcasses were cured into bacon by the Wiltshire process. Those from pigs fasted longer gained less weight after pumping with brine but also lost less weight during brine immersion and maturation. The overall yield of bacon, in relation to carcass weight, was therefore not affected by fasting. Consequently, the reduced carcass weight in the fasted pigs was carried through almost unchanged to the final yield of matured bacon. This was proportionately reduced by 0019 in the pigs fasted 24 h and 0043 in those fasted 48 h when compared with the control group.There was thus no evidence of any material reduction of yield differences during curing which could be caused by equilibriation of water in the carcass tissues with that in the curing brine. The implication is that losses in carcass weight in fasted pigs cannot be attributed simply to dehydration. Cured sides from fasted pigs tended to have proportionately slightly less weight in the ham and middle and more in the shoulder, and bacon from the pigs fasted 48 h was marginally less salty. 143

Effect of preslaughter fasting on the characteristics of pig livers

“…Pigs were killed at light pork weight for convenience of handling the animals in the accommodation available. Similar losses in liver weight and glycogen content have been found in bacon-weight animals (Warriss & Down, 1985;and unpublished observations) and the results on the composition and eating quality are likely to apply equally to pigs of heavier weight than used in these experiments.…”