A series of studies from Texas A&M University show that reflective aluminum-laminate covers can significantly reduce temperatures in dairy-calf hutches during hot weather, potentially improving calf welfare and weight gains.
Over several seasons and locations, Texas A&M animal scientist Ted Friend, PhD, has studied the effects of different types of covers on calf hutches. He initially compared two types of reflective laminate covers, aluminized low-density polyethylene or Al LDPE, reflective paint and uncovered control hutches. He used “black globe” thermometers to monitor temperatures inside and outside the hutches. The tests showed that the two laminate materials and Al LDPE produced similar results, with each reducing hutch temperatures compared with reflective paint and controls. While ambient temperatures and hutch temperatures fluctuated through the day depending on cloud cover, the covered hutches showed temperature advantages of 5 degrees or more during hot, sunny periods. The Al LDPE covers are considerably less expensive than the laminate covers though, so ongoing studies focused on that material.
In their tests, the researchers used black-globe thermometers in the hutches at one foot and three feet above the ground, corresponding with the typical height of a calf’s head while lying down or standing. They found that during the heat of the day, temepratures at 3 feet were considerably higher – as much as 5.6 degreees, than those at 1 foot, demonstrating that calves probably are more comfortable lying down than standing in hutches during hot weather.
Interested in how cooler temperatures might affect calf performance, the thee researchers conducted field tests on dairies in western Texas and Arizona. In one set of trials, the improved weight gains in covered hutches ranged from .039 pounds per day, or 3.1 pounds over 80 days, to .099 pounds per day or 7.93 pounds over 80 days.
In an Arizona trial in which the backs of hutches were raised with cinder blocks for ventilation, the covered hutches reduced temperatures by 3.9 degrees, reduced calf panting during hot periods and improved gains by 7.5 pounds over 65 days.
For all practical purposes, the Al LDPE is as effective as laminate material that can cost 10 times as much, and the AI LDPE performs better under farm conditions,” Friend says. “The fabrication of the covers and the mounting system has steadily improved over recent years and will be available for purchase as Cool-Calf Covers.”
Read more from Texas A&M.