ARS | Publication request: Heat and moisture production of growing-finishing barrows as affected by environmental temperature

Submitted to: Proceedings of the American Society of Agricultural and Biological Engineers International (ASABE)
Publication Type: Proceedings
Publication Acceptance Date: June 16, 2008
Publication Date: August 4, 2008
Repository URL: http://www.asae.frymulti.com/
Citation: Nienaber, J.A., Brown Brandl, T.M. 2008. Heat and moisture production of growing-finishing barrows as affected by environmental temperature. American Society of Agricultural and Biological Engineers. Paper No. 084168. St. Joseph, MI:ASABE.

Interpretive Summary: Heat and moisture production are critical information for sizing ventilation equipment like heaters and fans. Those values were adopted as standards for swine production buildings by several professional organizations. However, the original standards were based on measurements that were made 30 to 50 years ago. Modern swine, which are more lean, and modern feeding programs have caused changes in both heat and moisture production of swine. This paper presents the results of a study on barrows during a normal period of growth at a wide variety of environmental temperatures within a laboratory. Additional studies are planned using gilts in the same laboratory. Similar studies are being proposed to be done in the swine buildings themselves. These data, along with existing data already published, will lead to updated standards for ventilation system design.

Technical Abstract: Heat and moisture production measurements were completed on barrows over the normal weight range of 60 to 120 kg and a temperature range of 16 to 32°C. All measurements were based on a 21-hr period and adjusted to a 24-hr base. Animals were acclimated to treatment temperatures for 2 weeks, and then moved to calorimeters maintained at that respective temperature. After calorimetry was completed, chamber temperatures were adjusted to the next treatment temperature. The process was repeated until all 30 animals were exposed to each of 5 treatment temperatures. Heat production decreased, feed intake decreased, and moisture production increased as environmental temperature increased. Heat production was directly affected by the level of feed intake as measured by the average daily feed consumption over four days prior to calorimetry measures. Dynamic measurements of heat production showed variable increases in heat production dependent on environmental temperature up to the time lights were off, followed by declines in heat production during night time and immediate increases again with lights on, again dependent on treatment temperatures. Measurements on gilts will be completed in a companion study.