Physiological response of dromedary camels to road transportation in relation to circulating levels of cortisol, thyroid hormones and some serum biochemical parameters

Abstract

Transportation is often considered as one of the main causes of stress raising considerable interest, both in economic and animal welfare terms. The objective of the current study was to determine physiological response of dromedary camels to road transportation in relation to circulating levels of cortisol, thyroid hormones and some serum biochemical factors during summer conditions. Ten Iranian dromedary camels, five males and five females, were selected for the study. The study was conducted on three consecutive days in August 2008. At first day, blood samples were collected at 08:30 A.M., 09:30 A.M. and 01:30 P.M. to determine any possible variation in individual measurements due to diurnal changes or as a result of food and water deprivation for 5 h. Travel commenced on day 2 at 08:30 A.M. for 5 h, with a total of about 300 km traveled. At second day, blood samples were collected immediately before loading, at 08:30 a.m., after 1 h transport, at 09:30 A.M., and on the end of transportation, after unloading, at 01:30 P.M. Final blood sample was taken 24 h after arrival. In the current study no significant difference was observed in any parameter between sexes at each sampling time. The data related to day before transport had no significant differences between different times except for values obtained for cortisol that at 01:30 P.M. showed a significant decrease in comparison with data at 08:30 and 09:30. Circulating cortisol, T(4), T(3) and fT(4) levels was significantly higher after transportation compared with pre-transport values and returned to basal values within 24 h after transport. Transportation had effects on metabolism as demonstrated by increase in serum concentrations of glucose, NEFA, and urea nitrogen. Serum concentrations of glucose, NEFA, and urea nitrogen returned to basal values in final bleeding at 24 h after transport termination. In the current study transportation had no significant effects on serum concentrations of fT(3), triglycerides, cholesterol, beta-hydroxybutyrate, albumin and total protein. Taken together, the results obtained for short road transportation of dromedary camels showed a strong physiological response and provide some biomarkers for stress detection in this species. Further research to validate these potential biomarkers is necessary.