Think Seriously about Heat Stress on Dry Cows
Many dairies have adopted heat abatement programs for lactating dairy cows. But, what about the dry cows? Do you have the attitude, "So, who can afford heat abatement equipment for dry cows? How am I going to get paid back for making them more comfortable?"
Using data from Florida (the southern most state in eastern US) a research team looked at the consequences of heat stress on not only the cows but subsequent milk production of their daughters and grand-daughters.
They found significantly lower production among the daughters and even the grand-daughters of the heat stressed dry cows compared to cows that had experienced heat abatement during their dry period.
Grand-daughters from heat-stress grand-dams produced in their first lactation 8 pounds/day (3.7kg) less milk when compared to their herd mates whose grand-dams had experienced heat abatement environments. when all other factors were accounted for. [63 pounds/day (28.5kg) compared to 71 pounds per day day (32.2kg)]
During their second lactation these same cows from heat-stressed grand dams produced 14 pounds/day (14.3kg) less milk when compared to their herd mates whose grand-dams had experienced heat abatement environments when all other factors were accounted for. [75 pounds/day (34kg) compared to 89 pounds/day (40.5kg)].
Reference: Laporta, J. and Others, "Dry period heat stress reduces dam, daughter, and grand-daughter productivity." 2018 ADSA abstracts JDS Vol 101, Suppl 2 p151