Pigs were selected at random from three lines (homozygous halothane positive, homozygous negative, and the heterozygotes). They were housed for four weeks within standardized environmental conditions with six pigs per pen corresponding to each of the three lines with two treatment combinations (6×3×2). Half of the pigs were allocated to routine care without humans entering the pen, while the other ones received an increased human contact treatment; animal-man interaction times were recorded. Before and after the four-week experimental period, pigs were housed individually for one day. A blood sample was taken for beta-endorphin analysis and heart rate was measured. The final heart rate measurements were continued during a transport of two hours. With respect to animal-man interaction times no clear treatment effect was observed. Increased human contact lowered the plasma beta-endorphin content to a greater extent as a function of time, while heart rate also became lower. The latter may result in an improved heart function during handling and transport. Differences with regard to the halothane gene were observed during housing conditions, but not during transport.
