Nitrogen-Corrected Apparent Metabolizable Energy Value of Crude Glycerol for Laying Hens / Współczynnik Metaboliczności Energii Surowej Gliceryny Dla Kur Nieśnych

An experiment was conducted with 64 Tetra SL laying hens (placed into four groups) to determine the AMEn value of feed grade crude glycerol (DM 92%; glycerol 86.80%; methanol 0.04%; fat 0.49%; ash 4.67%; GE 15.59 MJ/kg). All groups were given a 100 g basal diet per day (AMEn value 11.46 MJ/kg; protein 16.97%; Ca 3.49%; P (non-phytate) 0.56%; lysine 0.82%; methionine 0.40%; cysteine 0.29%; threonine 0.60%; tryptophan 0.19%), which was supplemented with 5%, 7.5% and 10% glycerol for the three experimental groups. Hens were placed in metabolism cages (4 hens/treatment in four replicates). After a 10-day adaptation period, excreta was collected and weighed individually for 10 days. The AMEn value of crude glycerol (86%) was calculated as 15.30 MJ/kg for laying hens. During the experiment, egg production (90.0-90.8%), egg weight (56.8-58.0 g) and egg mass (51.2-52.7 g) were not affected by dietary treatments. Feed conversion was significantly reduced by a 10% glycerol supplementation. We concluded that crude glycerol’s energy is efficiently used by laying hens, and more efficiently than by broilers. The established 15.30 MJ/kg AMEn value of crude glycerol when fed in the daily ration to laying hens means that they utilized 97.6% of the glycerol’s GE content.