As an overall conclusion, climate factors seem to be
highly relevant for conception rate, especially during
the period 3 days before to 1 day after AI. The use of
maximum temperatures gives more information that the
one provided by THI variables. Thus, the use of the THI
or temperature to control a farm environment would
depend on the individual farm and on each environmental
situation, but it is important to check temperature
and humidity to know when to adopt cooling
measures. Practical implications are for example,
implement of fans that open at 70–75 THI units and
increase management practices around AI day. We
obtained our climate data from a meteorological station
6 km within the herds. It is likely that the different
management systems applied in these high producing
dairy farms changed the environmental conditions. For
example, fans, cool water, correct ventilation could
have changed environment of dairy herds. Further
studies should try to establish real climate conditions at
the farm level