The Cool-Calf Covers™ Story:
Cool-Calf Covers™ are the result of more than eight years of university research and testing by Dr. Ted Friend at Texas A&M University. Several of his lab’s published studies are listed below, but many more studies on cooperating farms in Central Texas, the Texas Panhandle, and Arizona were also conducted by Dr. Friend and his students.
Plastic calf hutches sitting in the sun get a lot hotter than ambient temperature. Dr. Friend’s students documented that air temperature in hutches as they are heated by the sun, often reaching 113 – 116°F on clear days, even with a breeze. Like other researchers, Dr. Friend tried moving hutches under shade cloth or under buildings, but that eliminated the benefits of the sun in drying out pens and hutches and decreasing pathogens. Exposure to sunshine is what has helped make hutches the “gold standard” for raising calves, and these covers keep the sun from heating them up.
One of the first things tested were reflective coatings and paints, but those were expensive and did not prove nearly as effective as highly reflective covers. Also, producers would be stuck with painted hutches during the winter, which is counter-productive when absorption of the sun’s heat is important.
Reflective films from the construction and packaging industry were tested on farms, but they were expensive and most did not survive 90 days on hutches in Texas trials. Aluminized low-density polyethylene (Al LDPE) showed the most promise, so tests were conducted to determine optimum thickness of the material and ways of mounting it on hutches to best resist wind stress. Al LDPE is the same material used in many “rescue blankets” that are popular with paramedics and back packers, but is fabricated in the USA specifically to Cool–Calf Cover™ standards by Star Metalizing of Oceanside, CA.
A very popular brand of hutches has a emissivity (inverse of reflectiveness on a 0 to 1 scale) value of 0.84, which is why they heat up so much when in the sun. A Cool-Calf Cover™ has an emissivity of 0.08 - 0.09, which indicates it is highly reflective . Studies found that the inside ceiling peak temperature over 21 days was significantly (P<0.001) less in hutches with reflective covers (99.5°F) than hutches without reflective covers (106.9°F). Not only do the high temperatures of the ceiling and walls heat the air, but the hot surfaces also emit radiant heat that contributes to a calf’s heat load.
University research has found that Cool-Calf Covers™ significantly reduce air temperature, radiant heating, and panting in calves, while helping to improve weight gain, immune function and the comfort of calves. The covers also eliminate the need of elevating the back of calf hutches to increase ventilation, which also makes anchoring hutches to the ground more difficult in the event of wind storms.
Cool-Calf Covers™ arrive folded into 18" wide rolls containing 50 covers weighing about 50 lbs per roll. The covers are perforated at the correct intervals and have been tested on rectangular Calf Tel, Poly Dome and Agri Plastics calf hutches. The covers are generously cut so they will also likely fit other brands or designs that when measured over the widest part of their roof from one base to the opposite side, are less than 138”. For advice on fitting over the Poly Dome Square Hutch roof vent, see Mounting Instructions for easily cutting a hole to accommodate the vent. Cool-Calf Covers resist tearing and can be easily sliced or cut with inexpensive, but sharp, scissors.
Cool-Calf Covers may close off some vents on the roof and sides of some models of hutches. Remember, those vents were put there because the hutches heat up in the sun, which is prevented by the covers.