Pig body heat output
What is the average anticipated heat loss to the atmosphere of the following pigs in Btu/hr sensible and latent? 20 lb piglet 50 lb weened pig 100 lb feeder pig 200 lb finished pig ready for market Thank you
Hennepin County Minnesota swine
The sensible and latent heat loss from pigs has been increasing over the past 30 to 40 years with the genetic changes made in various breeds to improve both average dairy gain and feed efficiencies in pigs. So the heat and moisture production values are a moving target with an estimated increase of between 12 and 35 % from pre 1988 pigs to pigs from the early 2000's as found in a recent literature review study published in 2004 (Brown-Brandl et al., 2004). So with that caveat here are sensible and latent heat loss (production) data for the 4 weight categories of pigs requested.
20 lb (9 kg) pig = 185 BTU/hr (sensible)
*latent (moisture) loss est. at 80 BTU/hr
50 lb (23 kg) pig - 390 BTU/hr (sensible)
*latent (moisture) loss est at 150 BTU/hr
*as the literature study indicated there is very limited data on latent or moisture production data for young or nursery pigs. ASAE standards suggest latent heat from 30 to 60 % of the total heat production depending on ambient temperature, the higher the temperature the greater the % of latent heat.
100 lb (45 kg) @ 75 F = 520 BTU/hr (sensible) and 154 BTU/hr (latent)
200 lb (90 kg) @ 68 F = 890 BTU/hr (sensible) and 154 BTU/hr (latent).
The last two values for the larger pigs weights are from two recent studies completed at the USDA-ARS US Meat Animal Research Ctr near Clay Center, NE (Nienaber & Brown-Brandl, 2008 and Brown-Brandl et al., 2011).
This is exactly the information I am looking for.