Pre-slaughter administration of glycerol as carbohydrate precursor and osmotic agent to improve carcass and beef quality

Glycerol is a by-product from biodiesel production. This molecule is a carbohydrate precursor, thus it maintains the pH of beef at below 5.8 after slaughter, contributing to the prevention of Dry Firm Dark (DFD) meat. Furthermore, glycerol osmotic properties could contribute to alleviating the effects of some stress situations. The aim of this study was to evaluate the effect of administering crude glycerol (2 g kg−1 body weight; via nasogastric tube or in drinking water) 24 h prior to the slaughter of young bulls, on plasma parameters, liver glycogen levels, carcass (body weight, dressing percentage, carcass weight and length), and beef quality (proximal composition, pH, colour, water holding capacity (WHC), drip loss, cooking loss, and sensory attributes). In general, the plasma parameters and liver glycogen were not affected by glycerol administration (P>0.05). Transport had a significant effect on total protein, albumin, glucose, sodium, potassium, chloride, and lactate plasma levels. Carcass parameters, proximal composition, pH, colour and sensory attributes were not affected (P>0.05) by glycerol treatment but WHC was (P<0.05). The glycerol did not affect the stress markers in plasma during the transport, carcass or meat quality negatively, but it seems to improve WHC of beef.