Evaluation of thermoregulation of horses (Equus caballus) submitted to two methods of post-exercise cooling, in hot and humid climate conditions, in the Eastern Amazon.
Abstract: In Brazil, the study on equine thermoregulation has not shown considerable advances, moreover, in the Amazon, this is a little explored aspect. This study aims to evaluate the thermoregulation of horses submitted to two methods of post-exercise cooling, in the climatic conditions of the Eastern Amazon. The experiment was conducted at Centro Hipico, Ananindeua, Para, for 15 days. Ten male horses, castrated of the Brazilian breed, aged 13 years and with an average weight of 482.3 kg were used. Equestrianism, which was exercised with pre-established protocol in the arena and track, for 30 min. After the exercise, the animals were divided into two groups for application of the treatments, which were two cooling methods, such as a bath with water at room temperature (about 25°C) and a hiper cooling method (6-9°C). During the experimental period, air temperature (AT) and relative humidity (RH) data were recorded and the Temperature and Humidity Index (THI) was calculated. Data from the rectal temperature (RT), heart rate (HR), respiratory rate (RR) and Body surface temperature (BST) of the animals were also measured at three moments: before exercise, after exercise and after applying the cooling methods. The adaptability index used was the Benezra Thermal Comfort Index (BTCI). The BST was performed with the help of infrared thermograph, which were the left side of the neck, thorax, rump, and right side to the armpi, before the exercise, after the exercise and after applying the cooling methods. The statistical design was completely randomized. Analysis of variance was performed using the GLM Procedure of SAS 9.1.3. After the application of the cooling techniques in the animals, the AT and THI were higher and the highest RH values were found before the exercise (87.21%). The highest RT, RR, HR, BST, and BTCI values were observed after exercise. There was no significant dierence ( > 0.05) between cooling methods. There was a highly significant and positive correlation ( < 0.01) between all physiological variables (RT, RR, HR, and BST) and the Iberian Index with AT and THI and negative with RH ( < 0.01), thus demonstrating the influence of the environment on the thermoregulation of animals. It is concluded the evaluation of stress, welfare and thermoregulation of horses submitted to two methods of post-exercise cooling, in the climatic conditions of the Eastern Amazon, demonstrated that the studied cooling methods showed to reduce the rectal temperature, the respiratory rate, the heart rate and the body surface temperature with equal efficiency. However, in terms of practical ease of use, the room temperature water cooling method has proven to be more practical.
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This research aimed to evaluate the effectiveness of two cooling techniques used for horses after exercise in the hot and humid conditions of the Eastern Amazon. The study found that both methods – bathing with room temperature water and an advanced cooling technique – were equally effective in reducing the animals’ body temperature, heart rate, and respiratory rate. However, the simpler method of using room temperature water proved to be more practical.
Study Overview and Methodology
The study was conducted at Centro Hipico, Ananindeua, Para, in Brazil. Over 15 days, ten 13-year-old horses of a Brazilian breed were exercised for 30 minutes each day.
Following exercise, the horses were divided into two groups. One group was cooled with a bath of room temperature water (approximately 25°C), and the other with a more sophisticated cooling method using colder water (6-9°C).
The research monitored key metrics at three moments – before the exercise, after exercise, and after applying the cooling methods. These measurements included rectal temperature, heart rate, respiratory rate, and body surface temperature.
Environmental conditions during the study were also tracked, specifically air temperature and relative humidity. From these data, the Temperature and Humidity Index (THI) was calculated.
A specialized thermal comfort index, the Benezra Thermal Comfort Index (BTCI), was used to examine the horses’ ability to adapt to the environmental conditions.
The researchers applied a completely randomized statistical design and employed the GLM Procedure of SAS 9.1.3 for a variance analysis.
Key Findings
Following the application of the cooling techniques, the horses demonstrated higher air temperature and THI values, with relative humidity being highest before exercising.
The highest values for rectal temperature, heart rate, respiratory rate, body surface temperature, and the BTCI were all observed right after the exercise, before the cooling techniques were applied.
There was no significant difference in results between the two cooling methods. Both effectively reduced the physiological variables, indicating successful cooling of the horses.
Takeaways and Conclusion
There is a high and positive correlation between the horses’ physiological variables, including temperature, heart rate, and the Benezra Thermal Comfort Index, with air temperature and the Temperature and Humidity Index.
Contrarily, there was a negative correlation with relative humidity, suggesting that the environment significantly impacts the thermoregulation of the horses.
The study concludes that while both cooling methods effectively reduce the horses’ temperature, heart rate, and respiratory rate, the method using room temperature water is more practical and therefore preferable in these climatic conditions.
Cite This Article
APA
Lisboa BRF, da Silva JAR, da Silva WC, Barbosa AVC, Silva LKX, Lourenço-Júnior JB.
(2023).
Evaluation of thermoregulation of horses (Equus caballus) submitted to two methods of post-exercise cooling, in hot and humid climate conditions, in the Eastern Amazon.
Front Vet Sci, 10, 1150763.
https://doi.org/10.3389/fvets.2023.1150763
Institute of Animal Health and Production, Federal Rural University of the Amazon (UFRA), Belem, Pará, Brazil.
da Silva, Jamile Andréa Rodrigues
Institute of Animal Health and Production, Federal Rural University of the Amazon (UFRA), Belem, Pará, Brazil.
da Silva, Welligton Conceição
Postgraduate Program in Animal Science (PPGCAN), Institute of Veterinary Medicine, Federal University of Para (UFPA), Federal Rural University of the Amazon (UFRA), Brazilian Agricultural Research Corporation (EMBRAPA), Castanhal, Pará, Brazil.
Barbosa, Antônio Vinícius Corrêa
Cyberspace Institute, Federal Rural University of the Amazon (UFRA), Belem, Pará, Brazil.
Silva, Lilian Kátia Ximenes
Institute of Veterinary Medicine, Federal University of Pará (UFPA), Castanhal, Pará, Brazil.
Lourenço-Júnior, José de Brito
Postgraduate Program in Animal Science (PPGCAN), Institute of Veterinary Medicine, Federal University of Para (UFPA), Federal Rural University of the Amazon (UFRA), Brazilian Agricultural Research Corporation (EMBRAPA), Castanhal, Pará, Brazil.
Conflict of Interest Statement
The authors declare that the research was carried out in the absence of any commercial or financial relationships that could be interpreted as a potential conflict of interest.
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