PSIV-11 Description of a novel Calorimetric unit to determine net energy in group housed pigs

摘要

The Swine Calorimeter Unit (SCU) is being developed at the University of Illinois at Urbana-Champaign. The objective of the SCU unit is to be able to determine net energy (NE) of diets and ingredients fed on an ad-libitum basis to group-housed pigs in all phases of production. The SCU allows for calculating NE based on the indirect calorimetry procedure. There are 6 calorimetry chambers in the SCU. Each chamber is made air-tight by means of a gasketed surface, measures 1.8 × 2.1 × 2.7 m, has fully slatted floors, and a volume of 10.2 m3, with capacity to hold 4 to 10 growing-finishing pigs depending on size. There are manure screens and urine pans under the slatted floors. Each chamber is equipped with a fresh air supply system (Fantech, Lenexa, KS, and Accutrol LLC, Monroe, CT). Humidity and temperature in each chamber is controlled by a regulator unit (Parameter, Black Mountain, NC). The precision for maintenance of the temperature can be controlled with an accuracy of ± 0.1°C and relative humidity (RH) ±0.5%. These levels of precision are ensured by the use of a dew point control system. To measure the gas exchange in the chambers, the Classic Line system developed by Sable Systems International is used (Sable System International, North Las Vegas, NV). The air subsample first enters the methane analyzer, then the CO2 analyzer, and as the last step the oxygen analyzer. The gas analyzers provide readings in percentage units with high resolution (0.00001 to 0.01%) depending on gas concentrations. Those values are obtained in a determined period of time to be able to calculate total heat production from each chamber. Operation of the SCU will start in January 2019, and the initial objectives include comparisons of net energy in individually housed and group housed pigs.