The effects of fasting, electrolyte supplementation and electrical stimulation on carcass yield and meat quality in bulls

Abstract

Eighty-nine yearling beef bulls were allocated to one of four lairage treatment groups of either 0, 12, 24 or 36 h. Except for the 0-h group, all animals were given a 4-h road transport followed by either 12, 24 or 36 h in lairage pre-slaughter without feed and water. An electrolyte solution was offered during lairage to groups of bulls within the fasting treatments. Following slaughter and dressing, alternate carcass sides were stimulated (470 V, 1.5 A, 60 Hz) for 60 s, and data on muscle quality were collected. Fasting resulted in a progressive reduction in warm and cold carcass weight (as a proportion of final live weight) and reduced liver, rumen and intestine proportions. Electrolyte supplementation was effective in reducing carcass weight losses and appeared to have its greatest effect on bulls kept in lairage for 36 h. Fasting and electrolyte supplementation had few effects on muscle quality. Electrical stimulation reduced muscle shear value, lowered final muscle pH, brightened muscle colour at 24 h post mortem but had no effect on marbling score. It was concluded that electrolyte supplementation increased carcass yield in fasted bulls but had little beneficial effect on meat quality. On the other hand, electrical stimulation improved several quality parameters, including muscle shear value. Key words: Bulls, cattle, fasting, lairage, electrical stimulation, meat quality