Background and Aim: Estrus detection plays a crucial role in the success of animal reproduction. It was previously reported
that body temperature changes during estrus. This study aimed to investigate the relationship between vaginal temperatures
(VTs) measured by a data logger, ovarian activity, and hormonal cyclic changes in camels.
Materials and Methods: Six mature, healthy, non-pregnant dromedary, and 10-12-year-old camels were included in the
study. The ovarian activity was monitored with ultrasonography, and estrus behavior was evaluated using an active and
virile male camel. Animals were inserted with a blank controlled internal drug release device attached with an intravaginal
data logger. Every hour, the ambient temperature was recorded by another data logger. Blood samples were collected, and
sera were used to measure estradiol and progesterone levels.
Results: The whole follicular cycle lasted 25.41±1.36 days, and the maximum sizes of the dominant follicle in the first and
second follicular waves were 1.63±0.27 cm and 1.94±0.42 cm, respectively. There was a significant positive correlation
between the follicular diameter and estradiol-17β level (p<0.01, r=0.397). There was no correlation between the follicular
diameter and progesterone level (p>0.05, r=0.038), which remained low during the whole period of the experiment. The
mean daily VT was significantly correlated with the diameter of the dominant follicle (1.7-2.2 cm, p<0.01, r=0.52).
Conclusion: Measurement of VT will improve the accuracy of estrus prediction. Further studies are recommended to
validate VT in camel reproduction.