Carbob dioxide is produced many from animal respiration, however other factors such as manure release, outside air and combustion heating systems also contribute to production. Problems tend to rise with carbon dioxide in cases when power fails for several hours allowing levels to build within the barn. This study set out to measure carbon dioxide concentration levels at frequent intervals, investigate the production rate of carbon dioxide and evaluate the impact pig weight, ventilation rate and temperature have on production and concentration.

Average carbon dioxide concentration throughout the experiment was 936 ppm at the pit fans, 1,017 at the wall fans and 1,227 in the pit headspace. Carbon dioxide concentration levels were found to be inverselt porportional to the ventilation rate and inside/outside temperature, while being directly porportional to pig weight. Carbon dioxide production ranged from 45 to 348 kg/hr averaging 111 kg/hr with a average pig weight of 49,143 kgs. Average carbon dioxide producton and ventilation rate revealed two peaks at 9:00 am and 3:00 pm throughout the day. This was not evident in other studies, however similar results were found with ammonia production (Ni, 1998). Carbon dioxide production was directly porportional to temperature, ventilation rate and pig weight. Carbon dioxider production rates were higher for this study with respect to Ni (1998), however higher temperature and ventilation rates account for the difference.