Effects of altered ambient temperature on metabolic rate during CO2 inhalation.

The research investigated how changes in ambient temperature affect the metabolic rate in ponies when inhaling CO2. The results found that inhalation of CO2 increased oxygen consumption and affected thermogenesis in ponies, with higher ambient temperatures leading to elevation in these processes.

Research Methodology

• The study observed twelve ponies as a part of their experimental population. The ponies were exposed to multiple levels of inspired CO2 (known as PIco2) – less than 0.7, 14, 28, and 42 Torr.
• The exposure was conducted for 30-minute intervals across two seasons – winter and summer, with different ambient temperatures for each season.
• The winter tests were carried at 5 and 23 degrees Celsius while the summer tests were conducted at 21, 30, and 12 degree Celsius.

Results

• In both summer and winter, an increase in ambient temperature led to a rise in pulmonary ventilation and breathing frequency, but no considerable increase in the consumption of oxygen.
• A decrease in ambient temperature during summer resulted in a reduction in ventilation and breathing frequency without significant changes of oxygen consumption.
• During neutral ambient temperature (average temperate weather conditions), an increase in the levels of PIco2 resulted in a proportional increase in oxygen consumption.
• The increase in oxygen consumption was less profound during higher ambient temperatures and was more pronounced during colder temperatures in summer.
• The study also found that respiratory heat loss (RHL) had an inverse relationship with the ambient temperature — higher ambient temperatures resulted in lower RHL.

Implication of Findings

• The research provided critical insights on the physiological response of mammals, as exemplified by ponies, to various levels of inspired CO2 at different ambient temperatures.
• This study contributes to our understanding of how increased CO2 levels and temperature changes might affect metabolism and thermoregulation in animals.
• Such a study may be critical for those managing animal health in variable climates or where there are concerns about air quality.