Biological Effects of Hutch Covers in Reducing Heat and Cold Stress in Individually Housed Dairy Calves
Abstract
Two studies were conducted to evaluate the biological effects of hutch covers in reducing heat and cold stress in individually housed dairy calves.
The heat stress study was conducted on two farms, one in Arizona (AZ) and one in the Texas Panhandle (TX). Biological parameters were used to compare unweaned calves housed in reflectively covered hutches with calves in uncovered hutches. Average daily maximum temperature was 7.78 ºC warmer (P < 0.01) at AZ than at TX throughout the study. Internal hutch temperature of the reflective covered hutches was 2.16 ºC cooler (P < 0.05) at AZ, and 2.57 ºC cooler (P < 0.05) at TX than control hutches during the hottest 4-h portion of the day. Respiration rates at AZ were lower (P < 0.01) for reflectively housed calves than for control calves. While housed in reflective hutches, fewer (P < 0.05) calves were treated for ear infections than control calves and at 4 months of age, fewer calves that had been housed in reflective hutches were treated for pneumonia than control calves, possibly indicating long-term benefits. Reflective covers did not affect (P > 0.05) weight gain or immune response to an IBR vaccination at either farm. Reflective hutch covers moderate internal hutch temperature to a degree that can affect biological function. Absence of persistent infected calves with BVD, and high antibody titers to IBR indicate the farms’ vaccination and biosecurity practices against BVD and colostrum programs were successful.
The cold stress study was conducted during two consecutive winters in the Texas Panhandle. Unweaned calves housed hutches covered with 2 different materials (reflective and non-reflective) were compared during two consecutive winters (Trial 1 and Trial 2). Average daily temperature minimums were colder (P < 0.01) during December and January of Trial 1 than of Trial 2. Internal hutch temperature was 1.22 ºC warmer (P < 0.05) in reflective hutches and 0.67 ºC warmer (P < 0.05) in non-reflective than control hutches covers during the night of both trials but, was not different (P > 0.05) during daylight hours (0800-2000). Hutch covers demonstrated heat-retaining abilities but did not have a conclusive effect on ADG.
In conclusion, reflective hutch covers effectively moderate internal hutch temperature during sunny summer days, but not during winter.
Subject
dairyCitation
Haberman, Jade Ashlee (2015). Biological Effects of Hutch Covers in Reducing Heat and Cold Stress in Individually Housed Dairy Calves. Master's thesis, Texas A & M University. Available electronically from https : / /hdl .handle .net /1969 .1 /155734.