Infrared thermography relationship between the temperature of the vulvar skin, ovarian activity, and pregnancy rates in Braford cows.

The objective of this study was to compare the presence of ovarian activity and pregnancy rates to temperature variation at the vulvar skin measured by infrared thermography (IRT). In addition, we also aimed to evaluate the IRT as a non-invasive method to evaluate animal breeding from fixed timed artificial insemination (FTAI). The study comprises 150 non-lactating beef Braford cows (5/8 Hereford × 3/8 Nellore) aged between 3 and 10 years. Data were collected along the FTAI protocol period during animal management. Animals were subjected to reproductive ultrasound evaluation and thermal images were performed by an infrared camera. Mean skin vulvar temperature (°C) and ovarian structures data were compared using Tukey's t test used as follow-up test to ANOVA. We observed a statistical difference in the mean vulvar skin temperature between animals that had the presence of ovarian follicles (34.2 ± 1.8) compared to no activity (35.4 ± 1.0; P < 0.05). However, vulvar skin temperature were similar between pregnant (34.5 ± 1.5) compared to non-pregnant (34.3 ± 1.9) animals (P > 0.05). In conclusion, the IRT technique was efficient to detect changes on vulvar skin temperature observed during FTAI protocol in Braford cows. Therefore, the use of IRT as an indirectly diagnostic tool to detect ovarian activity seems promising and further studies are required to validate their potential in beef cattle production.