For several years now on our farm we have seen declining results in the June-September period. But never realized how much money heat stress really costs us!
The first thing we always see is a marked drop in production, especially in the 0 - 60 day group in lactation.
Last year we saw a decrease of around 2.3 liters of milk during this period. Unfortunately, loss of production was the least of my worries. Like every year, we saw our somatic cell count rapidly rise, although, fortunately it started to fall again in October.
This year we also had significantly more E. coli mastitis during and just after the really warm days, we even had to cull 2 cows . Fertility seems to be our biggest challenge due to heat Stress, our veterinarian advised us that the number of pregnant cows after 1st insemination had decreased by more than 40% between June-August, even in the Autumn -Winter months some cows are still not pregnant.