Current poultry housing environmental controllers do not directly factor in the state of the birds themselves, such as their deep body temperature (DBT) responses. In this article, we propose and investigate the feasibility of a new approach for real-time closed-loop control of poultry DBT under heat stress conditions using variable air velocity. Using five commercial breed broilers, an experimental tunnel ventilation enclosure placed inside an environmentally controlled chamber, implanted radio telemetry sensors, and a programmable logic controller (PLC), four experimental trials were conducted using a proportional-integral type feedback controller. The results indicated that (1) air velocity has a measurable, dynamic, and almost immediate impact on DBT of birds under heat stress; and (2) DBT of heat-stressed broilers can be maintained below a setpoint by varying air velocity using feedback control. These preliminary results suggest that using DBT as a feedback variable to manipulate air velocity within poultry housing is a promising approach. This article represents a first step towards the design of the future poultry environmental controller that responds directly to the physiological needs of the birds.

Radio Frequency Identification (RFID) technology is commonly used for object or animal identification and tracking. In this article, we explore the feasibility of its use in a rapid solution to wireless real-time monitoring of soil properties. A lab prototype system for wireless measurement of temperature was developed using a commercially available 13.56-MHz RFID passive tag. Temperature is sensed by a thermometer Integrated Circuit (IC) that produces a Pulse Width Modulated (PWM) signal. An embedded Motorola 68HC11 microcontroller monitors this signal, produces averaged measurements, and sends them to the RFID "tag" or transponder unit, hence the "smart" feature of the sensor A receiving unit also called the "interrogator" emits an electromagnetic field, which when detected by the passive RFID tag causes it to transmit temperature data stored in its memory to the interrogator. The latter detects these measurements and sends them to a data collection PC. The architecture of the sensor allows for the addition of other transducers without alteration of the telemetry, channel or significant changes to the sensor design. In benchmarking tests using a water bath over the course of several days, measurement error over a range of 0 to 50degreesC showed a standard deviation of 0.5degreesC and a max error of 1.5degreesC. Measurements also showed a high correlation (greater than 99%) with those obtained using a thermocouple. The architecture of the developed wireless sensor prototype allows for additional soil transducers to be integrated into it without changes to the sensor design. Potential applications for this sensor could be in the area of precision farming where soil properties such as temperature might be monitored in a wireless manner Although limitations in transmission range (less than one meter) would require proximity, reading of the sensor using existing equipment that regularly pass over the field as a mount for the interrogator such as center pivot booms or sprayers, would increase feasibility of this telemetry strategy.