Application of infrared thermography as a determinant of estrous conditions of Sapera dairy goats

Abstract

Importance of the work: Detecting a goat’s estrous usually involves invasive methods that are less accurate because they are subjective, require significant time and resources and may cause problems with animal welfare. Infrared thermography (IRT) is one alternative solution because this method is modern, non-invasive and safe.
Objectives: To investigate the capabilities of IRT to predict and detect estrous in goats.
Materials & Methods: Twelve Sapera dairy goats were synchronized using CIDR® containing 0.3 g of progesterone for 18 d and an injection of serum gonadotropin at a dose of 400 international units intramuscularly 48 h before CIDR® withdrawal. Visualization of the estrous response, vaginal (T_vaginal) and rectal (T_rectal) temperatures, Draminski® score and IRT sensing results on the vulva (IRT_vulva) and rectum (IRT_anal) were measured six times daily starting at the time of the CIDR® withdrawal.
Results: All goats showed the onset of estrous at 24–32 h after CIDR® withdrawal. T_vaginal (mean ± SD, 39.20 ± 0.13°C), T_rectal (39.20 ± 0.15°C), IRT_vulva (37.03 ± 0.17 °C), and IRT_anal (37.04 ± 0.10°C) during estrous were higher than normal conditions. The Draminski® score was in the range 356–373 at the time of estrous. IRT_vagina and IRT_anal were positively correlated with T_vaginal and T_rectal, but not with the Draminski® score.
Main finding: IRT is a promising non-invasive tool for reproductive management in goats to identify superficial temperature variations during estrous in the vulva or vagina. IRT sensing alone or in combination with estrous observation would increase the probability of estrus detection in goats.