Telemetry System Helps Scientists Study Heat Stress in Cattle

A temperature sensor and transmitter, placed inside a small capsule inserted into a cow, will help researchers more effectively measure the animal's core body temperature, according to Agricultural Research Service scientists and cooperators who studied the technology.

Gaining accurate information on an animal's internal temperature is important for researchers who are conducting long-term heat stress experiments on livestock. Heat stress can kill livestock or reduce their productivity, causing losses for producers.

Agricultural engineer Tami M. Brown-Brandl of the ARS Roman L. Hruska U.S. Meat Animal Research Center in Clay Center, Neb., worked with agricultural engineers from several domestic and international universities to evaluate a commercially available telemetry system from HQ, Inc., of Palmetto, Fla.

The system consists of a capsule containing a temperature sensor, battery and transmitter, and a data recorder. For short-term measurements in pigs and poultry, the animal can swallow the capsule. For longer-term studies, the capsule is surgically inserted into the animal, where it can last for up to a year--an important advantage for long-term heat stress experiments. In cattle that Brown-Brandl studied, for example, a veterinarian inserted a three-inch-long capsule in each animal's abdominal cavity. The data recorders were placed on their backs to record body temperatures.

Past telemetry systems that were built to monitor wildlife had poor resolution. Other systems designed for medical purposes were precise, but too expensive. The new system is less expensive, but still gives good results. Researchers developed software to improve consistency of the data generated by the system.

ARS is the U.S. Department of Agriculture's chief scientific research agency.