The efficiency of operatnt thermoregulatory behavior in pigs as determined from the rate of oxygen consumption.

Pigs were trained to perform an operant response for a reinforcement of radiant heat and comparisons were made between oxygen consumption during sessions when extra heat was available and others when it was not. It was found that as judged by the rate of oxygen consumption the efficiency with which heat was obtained was very high when the radiation was allowed to increase air temperature, but declined when air temperature remained low. If the pig had to make several responses for a single reinforcement, there was no saving in oxygen consumption. Reducing the intensity of the heating led to a reduction in the frequency at which responses were made. When the reinforcement was a brief respite from a draught, the pigs performed a greater number of responses at low ambient temperatures, but this was not accompanied by any saving in the rate of oxygen consumption.