The present study examined sex differences and the involvement of gonadal hormones in stress responses caused by road transportation in Shiba goats. In experiment 1, we investigated the stress responses of males and females to transportation. Plasma levels of cortisol (Cor) significantly increased during 1 h of transportation, and those in females were significantly higher than those in males. Plasma glucose (Glu) and free fatty acid (FFA) levels also increased similarly in both females and males by transportation, and there were no sex differences. Food intake following transportation decreased only in males compared with that in the basal session, in which the animals were not transported. Experiment 2 examined the involvement of gonadal hormones in stress responses to transportation using castrated males. Goats were given cholesterol (Cho), 5α‐dihydrotestosterone (DHT) or 17β‐estradiol (Es). The plasma Cor levels increased during transportation regardless of hormone treatment, and those in DHT treated goats were significantly lower than those in Cho or Es treated animals. Plasma Glu and FFA levels also increased during transportation, regardless of hormone treatment, and there were no differences between treatments. Food intake following transportation was significantly lower than that in the basal session only in goats given DHT. In conclusion, gender affects Cor secretion that is increased by transportation and the decrease of food intake following transportation in Shiba goats, and the major cause of these differences is androgen.

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We investigated the physiological effects on goats of transportation for one hour in a small truck. We also investigated food and water consumption after transportation. Eight adult goats (four castrated males and four ovariectomized females) were used. Plasma levels of cortisol, glucose and free fatty acids increased significantly within 15 min of the start of transportation, and these higher levels were maintained throughout transportation. These results indicate that transportation in a small truck activates the hypothalamus-pituitary-adrenal (HPA) axis and the sympathetic nervous system in goats. Despite activation of the sympathetic nervous system, heart rate (HR) in subjected animals during transportation did not differ from during the control animals, which were housed in their usual pen. However, after the transportation had ended and the goats started to eat fodder, HR increased significantly. There was no difference in the amount of food consumption between the control and transported goats. Water consumption in the first three hours after transportation was significantly lower in the transported goats than in the controls for the equivalent period. In the subsequent three hours, however, the transported goats consumed more water than the controls. Consequently, the total water consumption of the transported goats did not differ from that of the controls during the six hours after transportation. In conclusion, short-term transportation with a small vehicle activated the HPA axis and the sympathetic nervous system in goats. HR was not increased during transportation, but after the transportation had ended HR in transported goats was higher than that in control goats. After transportation, goats had consumed the same amount of food as control goats, but water consumption during three hours after the transportation was lower than that of control goats. Figure 1 Schematic layout of the truck used for transportation in this study. The orientation of goats was perpendicular to the traveling direction of the truck, but the goats could reverse their position within each cage.Animal Science Journal (2008) 79, 526-533 **a significant difference was seen from the control test on the same period (P < 0.01). Data were represented as the consumed fodder and water during the period represented in left column. Transportation was conducted between 09.00 and 10.00 hours, and food was presented immediately after the transportation offset. In the control test, goats were kept housed in their usual pen over the same length of time as the transportation. Each data represents the average Ϯ SD of eight goats. 530 M. AOYAMA et al.