LIVERPOOL, NY — Most dairymen understand the benefits to keeping their lactating cow cool and comfortable during hot weather; however, according to Albert De Vries of the Department of Animal Sciences, University of Florida, keeping dry cows cool offers a return on their investment as well.
De Vries presented “Economic feasibility of cooling dry cows across the United States” at the recent Cow Comfort Conference, hosted by Cornell University Cooperative Extension North Country Regional Ag Team. The research completed by De Vries and his team, including Fernanda Ferreira, Rodrigo Gennari and Geoff Dahl, indicated that cooling cows during their dry period increases milk yield in the next lactation.
“Based on this study, it comes to 11 pounds increase per day for cooled cows,” De Vries said, compared with the control group of cows which received no cooling fans or soakers.
De Vries believes investing in the comfort of dry cows has been overlooked far too long. In his study, cows were cooled during the entire 45 days of their dry period using soakers and fans.
“It’s amazing how I’ve seen the size of fans increase over the past few years,” De Vries said. “They have doubled in number, too. Fans have been way too small way too long.
“You can go around the country and find good-sized losses of milk not made by dry cows not being cooled,” De Vries said.
He said based upon the 96 heat stress days in the U.S. per year, the 983 pounds of milk lost in its next lactation because of heat stress while dry, the economic losses per cow per year is $87. For farms with razor-thin margins and sizeable herds, that adds up fast.
Nationwide, farmers lose $810 million if cows lived under heat stress while dry.
The fixed cost of installing soakers and fans cost the same regardless of the heat outside and is little affected by the size of the herd. De Vries said the cost per fan unit is $700, maintenance costs $15, soakers are $8.19 per stall, energy demand charge is $37, and sand per dry cow stall is $90. In addition to those fixed expenses, the variable costs per heat stress day is $1.62 for electricity and $.0004 for water per liter.
By comparing the costs of adding cooling equipment for dry cows to the milk losses they will likely experience later, farmers can better estimate if the return on investment warrants cooling their dry cows, according to De Vries.
For farms that experience 90 or more heat stress days per year, “it may pay to build a new barn,” De Vries said. “It’s profitable to cool dry cows anywhere but the state of Alaska.”
Though they require a higher initial fixed cost than barn modifications, new construction can take advantage of structural changes that can build in better ventilation and reduce the variable costs involved with soakers and electricity use.
De Vries said the effects of cooling calf and heifer development were not included in his study.