Prognostic impact of neck responders on conception rate of Czech Fleckvieh Simmental cows

The climate in the Czech Republic is mild, transient between oceanic and continental, with a typical alternation of 4-year periods. The continental climate is characterized by high temperatures in summer and low temperatures in winter. During the extreme fluctuation of microclimatic conditions in the stable, there is also a change in individual reproductive indicators due to disruption of hormonal secretion, which further affects individual physiological processes, thus worsening conception or milder manifestations of heat, which we currently try to detect by neck responders and other modern systems.The experiment analyzed the effect of the average monthly temperature and humidity in the stable on the percentage of pregnant cows, in 2017 without the use of neck responders and in 2019, when all cows already had a neck responder. Monitoring was performed in 2017 and 2019 on the private farm GenAgro Říčany, a.s. (GPS 49 ° 12'32.319 "N, 16 ° 23'42.666" V). The values of average temperatures and relative humidity were calculated from 15-minute interval recordings of HOBO brand data loggers (Onset), which were placed in the stable, at the height at the withers of the cows without the possibility of influencing the measurements by the cows themselves. The object of monitoring was a herd of approximately 700 cows of Czech Fleckvieh Simmental various lactations. Data on the conception of cows were obtained both from the monthly reports of the breeding organization and from the data of the breeder.Thermal stress can have a long-lasting effect observable for weeks or months after the summer. This is also evidenced by the results of the work, which shows the worsening conception of cows, especially in late summer and autumn. At the same time, the results show a positive effect of the used neck responders, which help with the detection of heat and thus improve the reproduction of the whole herd.