Eustress versus distress in swine

Abstract

Two experiments were designed to determine Temptress phics. could be differentiated from distress in swine by measuring behavior, cortical, norepinephrine (E), and epinephrine (E). In Exp. 1, four barrows were assigned to two treatment groups: (1) Pigs acclimated to swimming (AS group) and (2) Pigs not acclimated to swimming (NS group). Pigs from both groups swam 6 laps per day (swim trial) for a total of four days (four swim trials; the time interval between each swim trial was 48 h. The schedule for blood sampling and behavior analysis during each swim trial was-10, 1. 15, 3.30, 5.45, 7.00, 10. 15, 12.30, 27.30, 57.30 min. In Exp. 2, the protocol was the same as Exp. 1 except that the time interval between each swim trial was 72 h. In Exp. 1, the differences in cortical AUC values between the NS and AS groups were substantial in the first (1056.93 :1: 96.50) and second (825.51 ::1: 170.62) swim trials. The differences in E AUC values between the NS and AS treatment groups were noticeable in the first (4.22 + .86), second (3.95 :i: .84), and third (3.68 :1: .42) swim trials. The differences in standard error (S.E.) for E between the NS and AS groups decreased over the four swim trials. In Exp. 2, the difference in cortical AUC values between the NS and AS groups was substantial in the second swim trial between the NS and AS groups were noticeable in the first (2.10 :1: .37) and second (2.71 + . 17) swim trials. The differences in S.E. for cortical between the NS and AS groups decreased over the four swim trials. The NS pigs appeared to behaviorally and physiologically acclimate to the swimming stimulus by the fourth swim trials their behavior and physiological profiles became similar to those of the AS pigs. The hormonal differences between treatment groups were associated with cortical and E. It appeared that the model for distress was represented by the psychogenic stress hormones, cortical and E, and that this distress was decreased with acclimation.