## 5 WST Applications
### Precision Livestock  
Modern animal production has changed in recent years due to the use of precision tools. Results of recent research have been used as inputs to preventive diagnostics and development of decision-making software in several areas, as well as to predict events.  
WST has been used as a new technique for measuring core body temperature that are minimally invasive and provide continuous, remote, real-time information. Together with body temperature WSN can obtain the oxygen saturation of cattle's blood using a pulse oximeter, location (GPS), ambient temperature and respiration [85].  
[PERSON] _et al_. created a wireless sensor network platform for animal health and behavior monitoring. A steer was instrumented with both internal and external sensors, using matchbox sized motes placed inside standard drug release capsules. The nodes monitored the intra-rumenal activity of the steer and communicate wirelessly with each other [60].  
[PERSON] _et al_. implanted an injectable RFID and temperature sensor, into the neck of horses in order to measure body temperature with a unique identity code [86]. [PERSON] _et al_. described the results of an experiment with a temperature sensor built into a bolus placed in the rumen of a cow. The main objective was to demonstrate that capsule-based wireless technology could work in cattle. The more in the rumen transmitted data to the mote attached to the front leg of the cow; from there the signal was transmitted to the base station [56].  
Evaluation of animal welfare can also be determined by wireless monitoring and enable the producer to make the right decision based on real-time management. [PERSON] _et al_. addressed and solved the problem of on-line monitoring of cows in an extended area, using ZigBee based wireless sensor networks. A study of wireless sensor networks applied to the monitoring of animal behaviour in the field is described. The problem of online monitoring of cows' presence and pasture time in an extended area covered by a strip of new grass using wireless sensor networks has been addressed [55,87].  
Monitoring and control of the quality of indoor environment is very important for animal health and welfare and directly impacts productivity and quality. Ventilation in the stables must be managed in order to avoid long-term over-critical exposure of the animals to ammonia, causing stress, pour health and reduced productivity. [PERSON] _et al_. presented a wireless, remote query ammonia sensor that can track both low and high concentrations of ammonia [88].  
At the same time, ventilation and heating must be minimized in order to save energy while keeping temperatures at an adequate level. [PERSON] _et al_. evaluated the capability and usefulness of WSN applied to monitor environmental variables in an animal housing facility. The nodes were moved through the facility to determine different profiles of temperature, humidity and luminosity [89].  
[PERSON] and [PERSON] develop a wireless data acquisition system for monitoring temperature variations in swine barns [90]. Powered from a single 3.6 V, 1,200 mAhr battery, and configured with a sample rate of 5 minutes the motes had a battery life of 3.5 years. Thus ZigBee motes, were found to be suitable for monitoring in confined animal feeding operations environments [90].