Effects of the experience of road transportation on the behavioral responses to it in goats

Abstract

The experience of a certain stimulus can affect the response to it. This study investigated whether the road transportation experience of goats affected their response to it. Six Shiba goats (15 - 30kg, 1 - 3 years age) were transported by truck for a duration of one hour on eight occasions, with the interval of 1 -7 days between each. A control test was also conducted, in which goats were loaded onto the parked truck for one hour. Three types of behavior, lying down, frequent changing the body direction, and foaming at the mouth, were observed to occur only when goats were transported and not in the control test. The latency from the start of transportation to the onset of lying down was significantly different across the transportation replicates; goats were observed lying down significantly faster after the third replicate than in the first (P < 0.05). In addition, the cumulative duration of the lying period was significantly longer after the fourth transportation than in the first (P < 0.05). Plasma cortisol levels, which were measured in the first, second, fifth and eighth transportations, were significantly increased by transportation (P < 0.01); there was no significant difference across transportation replicates. In the first transportation, plasma cortisol levels remained high even after the goats had been returned to their pens, and were not significantly different 60 min after transportation ended from those recorded during transportation. However, in the second, fifth and eighth transportations, plasma cortisol at 60 min after transportation ended had reduced to significantly lower levels than during the transportation (P < 0.05). At 60 min after transportation, plasma cortisol levels in the second, fifth and eighth transportations were significantly lower than those in the first (P < 0.05). The finding are consistent with the hypothesis that behavioral responses to transportation can be modified by its experience. Plasma cortisol levels indicated that road transportation can be highly stressful in goats, even after they have had multiple experience. However, goats showed that recovery times after transportation can be significantly reduced as a consequent of the repeated experience.