Apparent digestible and metabolizable energy content of glycerol in feed of growing pigs

Two experiments were conducted each with the same 12 pigs in the growing and finishing phase to determine the apparent digestible (DE) and metabolizable energy (ME) content of crude glycerol (86.76%) in feed compositions. Animals were randomly selected and placed into individual metabolism crates. Pigs fed basal diet supplemented with 0%, 5% or 10% of crude glycerol. A repeated 3 x 3 Latin square experimental design was applied. After an adaptation period of 10 days, feces and urine samples were collected for 5 days. Gross energy (GE) content of feed, feces and urine samples were measured in bomb calorimeter. The determined apparent DE and ME value of crude glycerol were 13.827 and 13.475 MJ/kg, respectively. These values represent 90.3% and 88.0% of GE. The results agree with DE and ME content of glycerol published by other researchers. DE and ME are not dependent on weight of pigs in the range of 25-85 kg and do not vary by the rate of crude glycerol in the diet (5% or 10%). According to our experiments diets different from usual corn-soybean meal feed did not influence utilization of glycerol. Feed grade glycerol can be considered a perspective feed component in diet of fattening pigs. (C) 2011 Elsevier B.V. All rights reserved.