[The course of plasma concentrations of cathecholamines and corticosteroids and of plasma--bound iodine (PBJ) in swine under the effect of noise and of various methods of raising].

Plasma concentrations of 11-OHKS were transitorily increased with significance in pigs, 25 kg to 45 kg in live weight, exposed to short-time engine noise (120 dB, 60 to 8,000 Hz, 60 minutes). Intensity of noise application and duration did not cause significant variation of plasma concentrations in catecholamines nor in P.B.J. The catecholamines were on a rising trend. Those results supported the conclusion that both quality and quantity of applied noise are perceived by store pigs as factors of disturbance. Their noise nature is comparable to that perceived by man and laboratory animals. Decline in 11-OHKS after 55 minutes of exposure to noise was recorded also by other authors who had exposed other species to long-time noise. It seems to reflect adaptation mechanisms in the information-processing system. The reactivity to noise of the adrenal cortext of swine was found to depend on the form of keeping. Animals kept in groups responded to noise in the same way in which they would respond to acute cold, by significantly increasing rise of plasma concentrations of 11-OHKS. The above results were taken to support the conclusion that organic response to a specific stimulus depended on the level of each control circuit at the time of stimulation.