Measuring heart rate, respiratory rate and body temperature using a finger pulse oximeter and an infrared thermometer in dairy cows

Abstract

Heart rate, respiratory rate, and body temperature are crucial indicators of animal health and welfare. Traditionally, heart and respiratory rates are often monitored with a stethoscope, while body temperature is measured rectally. These methods require handling the animals, which could potentially cause stress. Given the significance of these physiological parameters, this study aims to validate non-invasive techniques for measuring heart and respiratory rates with a human finger pulse oximeter and body temperature with an infrared thermometer. The study involved 40 Holstein Friesian cows at various lactation stages. The experiment was conducted in an alleyway using batches of 3-4 animals immediately after the morning milking. Heart and respiratory rates were measured using a stethoscope and a finger pulse oximeter, which were placed on both pigmented and non-pigmented teats, as well as on front and rear teats. Infrared temperatures of both front and rear teats were measured with an infrared thermometer, and rectal temperature was recorded with a digital thermometer. The Pearson correlation coefficient was determined using the PROC CORR of SAS 9.4 and the statistical significance was set as P ≤ 0.05. The finger pulse oximeter could not measure heart and respiratory rates in cows with pigmented teats. There was a high correlation between the stethoscope heart rate and pulse oximeter heart rate of front and, especially, rear teats (r = 0.79; and r = 0.85, respectively; P < 0.001). However, there was no correlation between the stethoscope respiratory rate and the finger pulse oximeter respiratory rate of front and rear teats (P ≥ 0.104). Similarly, there was no correlation between both front and rear teats and rectal temperatures (P ≥ 0.576). In conclusion, this study demonstrates that a finger pulse oximeter is a suitable tool for recording the heart rate in non-pigmented teats of dairy cows. However, further studies are needed to identify noninvasive methods for assessing respiratory rate and body temperature in dairy cows.