Submitted to: Applied Engineering in Agriculture
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/27/2007
Publication Date: 9/1/2007
Citation: Eigenberg, R.A., Brown Brandl, T.M., Nienaber, J.A. 2007. Development of a livestock weather safety monitor for feedlot cattle. Applied Engineering in Agriculture, Sept. 2007, Vol. 23(5): 657-660. Interpretive Summary: Summer heat can cause stressful conditions for feeder cattle, and in extreme instances these conditions can be fatal. A summer study was conducted to measure responses of cattle given shade and without shade. Respiration rate (RR), feed intake, and body temperature were the measurements made on the cattle. Environmental conditions were monitored over the same experimental period. A mathematical equation was developed for RR based on temperature, humidity, relative humidity, and solar radiation. These conditions were used to define stress limits on the cattle. The equations and the stress limits have been incorporated in a monitor for use at feedlots. The monitoring device, referred to as a Livestock Safety Monitor, includes a commercial weather station coupled to a microcomputer. The weather station collects current weather data that includes temperature, humidity, wind speed, and solar radiation. The weather information is transferred to the micro-computer, which calculates a level of concern ranging from normal to emergency, and alerts the feedlot operator.
Technical Abstract: Summer heat can result in stressful conditions for Bos taurus feeder cattle, and in extreme instances these conditions can be fatal. A study was conducted during the summer of 2001 at RLHUSMARC to determine physiological responses of cattle under shade or no shade conditions. The study involved eight steers assigned to individual pens, with four pens fitted with shade structures and the remainder had no shade available. Respiration rate (RR), feed intake, and body temperature were measured as response variables to the shade treatments. Environmental conditions were monitored for the experimental period. The resulting RR data demonstrated a 25C threshold for the treatment of shade/no shade. A linear regression was developed for RR that included effects of temperature, humidity, air speed, and solar radiation. Thresholds were developed from that linear relationship to relate RR to THI (Temperature-Humidity Index) to estimate thermal status of livestock. The equations and the corresponding thresholds have been implemented in a monitoring device for use at livestock production facilities. The monitoring device, referred to as a Livestock Safety Monitor (LSM), consists of a commercial weather station (Vantage PRO by Davis Instruments, Hayward, CA) coupled to a microcomputer (TFX-11, by Onset Computer, Pocasset, MA). The weather station collects current weather data including temperature, humidity, wind speed, and solar radiation. The weather information is transferred to the micro-computer where values alert the operator of current conditions that include: (1) normal, (2) alert, (3) danger, and (4) emergency. This report will summarize operating experience using the LSM.