“Additional study showed that in areas of water shortage, using water to cool heifers might not be the best use of this valuable resource,” Jordan said. “Unless heifers are moved out of their hutches for treatment, bedding becomes wet and a disease reservoir. And constructing permanent shades over hutches removes one of the key benefits of the hutches, which is to move them to ‘clean’ ground after each calf is raised. Plus, a permanent shade might be detrimental in the winter, when the sun’s rays help warm the calf.”
Friend said over the years the researchers have tested many different reflective films, including some laminates that were made to military specifications. But some of the most expensive material tested still could not last 60 to 90 days in the Texas sun without delaminating.
In the last year, he and his collaborators successfully identified a reflective material that is inexpensive, easily lasted from two to three months in the scorching Texas sun, and remained on the hutches until the calves were weaned and removed.
Study data showed interior ceiling temperatures in hutches with reflective covers were about 25 degrees lower than the control hutches used in the study at 10:30 a.m. and about 30 degrees lower at 2 p.m. on summer days.
“This large difference certainly influences the comfort of calves that seek shade within the hutches during periods when there is little wind. Over 10 days of on-farm trials, the highest daily peak temperatures at the level of a lying calf were 8.46 degrees lower in the hutches with reflective covers,” Friend said.
He said ambient and interior temperatures from covered and control polyethylene calf hutches over a 48-hour period showed cooler temperatures in the insulated hutches during the hottest time of the day, and the warmer temperatures during the night indicated the reflective insulation was useful during both hot, sunny days and cool nights.
“The design of covers from the fabrication process to the material and the mounting system is continuing to improve, and testing of the latest material and mounting system is now underway on several cooperating farms,” Jordan added. So the team’s goal of “developing a useful reflective cover that costs under $4 per hutch and lasts up to 90 days” is now within reach.
While the cover will be disposable, the bungees and PVC pipe required to attach the material to the hutch will be reusable, Friend said.