Resumen de Physiological adaptations of the pantaneiro horse to stress related daily work with cattle in the Pantanal, Brasil

C. McManus, H. Petzold, S. A. Santos, L.O.C. Silva, R. A. da Silva

• The Pantanal region of Brazil has some distinct bio-climatic characteristics making it a very hot and inhospitable environment. The only breed of horse that can support the long treks, and daily management of cattle in this environment is the Pantaneiro, that is a Iberian origin animal naturalized in the region through natural selection by centuries. This study aimed to evaluate the heart and respiratory rates (adaptation indicators) of Pantaneiro horses that daily work cattle in the Nhecolândia sub-region, Pantanal. Between the 5th and 8th of July 2003 these adaptation indicators were measured before, immediately after and 30 minutes after exercise on 12 horses, 7 of which were evaluated on two occasions, totaling 19 observations. The latter were evaluated in the morning and in the afternoon. The horses worked on average 5 hours in the morning and 8 in the afternoon. The heart rate immediately after and 30 minutes after exercise were 37.6, 50.0 and 46.1, respectively, in the morning and 42.8, 46.2 and 43.9 in the afternoon. Respiratory rate for the same times were 24.8, 36.6 and 35.1, respectively, in the morning and 29.3, 29.6 and 28.5 in the afternoon. Significant differences found between morning and afternoon measurements were probably due to na increase in environmental temperature. No significant differences were found between the three afternoon measurements. It was concluded that the Pantaneiro horse, used routinely in cattle work, is well adapted to exercise stress, and changes in physiological parameters are due to fluctuations in environmental temperatures.