A rectal thermometer is still the preferred device for assessing the body temperature of dairy calves.
According to new research from Purdue University, rectal temperature was a more reliable means of determining calf body temperature than an infrared temperature gun.
During the study, researchers used two different infrared guns to record body temperature at various locations on the body, including the muzzle, back, eye, base of the ear and peri-anal area. They also used the devices to record the temperature of hutch bedding material and outside pen floors.
The strongest correlation to rectal temperature occurred when infrared readings were taken at the base of the ear and the muzzle using an infrared gun that had both a surface and body temperature setting.
Although the infrared guns were not reliable when it came to calf body temperature (due to wide variations in temperature readings), they were much more precise when used to measure the temperature of solid surfaces, such as pen floors.
The research was presented in March at the 2011 American Dairy Science Association Midwestern sectional meeting in Des Moines, Iowa.
Body temperature measurements are an indicator of calf health, say the study’s authors. Guidelines for calf health can be found in the Dairy Calf & Heifer Association’s Gold Standards I.