2009 Annual Report
The second component will be conducted in a production system to determine MP by both the pigs and the housing systems. Two swine houses located at the USMARC will be used for these studies. Air temperature, RH, and CO2 concentration of both inside and outside will be recorded at 15-min intervals for a 24 hour period at least one time a week for the duration of the production cycle. Prior to initiation of the experiment each of the exhaust ventilation fans will be calibrated in-situ at various static pressures to develop the actual fan performance curves. Operational status of each exhaust fan will be monitored continuously. THP and MP data will be fitted to regression models each for barrows and gilts with main effects of temperature and body weight, using appropriate interaction, linear, and quadratic terms.
HMP rates are important criteria in building design. These HMP values provide the basis of design capacity for fans and heaters to control temperature and moisture in buildings. Temperature and humidity control are important, not only to maximize animal well-being and production, but also to prolong the life of the structure. Environmental temperature and animal size effects on HMP values are documented in published standards (ASAE Standards, 2003; ASHRAE, 2005). The unit received a grant from ASHRAE (American Society for Heating Refrigeration, and Air Conditioning Engineers) to conduct a series of studies to update the swine HMP values which will ultimately replace the numbers that are currently published in the standards book.
The grant will be partially completed through four calorimeter laboratory studies, with the objective of collecting total heat production (THP) from both barrows and gilts ranging in size from nursery age pigs through slaughter weight. In addition, the grant will support a series of field measurements to include a range of ages from farrowing, nursery, finishing, and gestating. The objective of the field measurement is to collect field scale moisture production and verify THP data collected in calorimeter laboratory studies.
Currently, we have completed the four calorimetry laboratory studies. One experiment using 96 nursery pigs was conducted; pigs were subjected to four environmental temperatures (20, 25, 30, and 35°C). A second experiment using 48 growing pigs was completed using temperatures of 18, 23, 28 and 33°C. Two experiments were conducted using 30 finishing barrows and 30 finishing gilts; the temperatures ranged from 16 to 32°C. The results of these lab-scale experiments are being summarized. Data summarization and analysis will need to be completed. The field measurements are currently in the planning phase. Modifications are being made to production facilities so measurements can be taken.