# A Smart Sensing System of Water Quality and Intake Monitoring for Livestock and Wild Animals
## 1 Introduction  
Water is an essential resource in animal agriculture and the number one nutrient required by ruminants [1]. Animal agriculture utilizes 30% of the total water in food production [2]. Given water's potential impact and a recognized need for improved technologies in rangeland agriculture [3, 4], farmers and ranchers continually seek ways to optimize their water management. This need has incentivized the development and utilization of innovations in agriculture. In drought-prone areas such as the southwestern United States, spatial and temporal variation in water availability results in reductions in forage quality and quantity, affects animal productivity, and influences natural resources management decisions. For example, in 2014, livestock producers proactively reduced their herds in response to drought, resulting in New Mexico beef cow inventories dropping by 53,000 cows [5]. In order to remain profitable under variable environmental conditions, livestock producers whose herds are efficient in feed and water use or who adopt water intake efficiency monitoring technologies to inform management decisions will improve fiscal resilience. Therefore, it is important to understand animal water consumption behavior based on both water quality and water access. Numerous predictive equations have been proposed related to water consumption in beef cattle. For example, in 1956, [PERSON] and [PERSON] authored a paper evaluating the effects of water intake from dry matter intake, air temperature, and bovine genus [6]. Since then, several equations have used additional variables such as salt supplementation, body weight, milk production, humidity, and wind speed [1, 7, 8, 9, 10]. Dry matter intake,air temperature, and body weight are the most common variables used to create these models. However, these methods along with many data sets were developed from cattle in confined situations, which do not represent the southwestern desert ecoregion [11]. Despite multiple water intake parameters being utilized in prediction models, water intake estimates vary greatly and have limited applications for producers in the US southwest. For instance, when a 489 kg lactating cow and standardized variable values are used, predicted water intakes range from 37 to 83 L per day per animal. Other variables not considered in these models are distance to water, climate, and elevation. Breed of cattle likely could have an impact on water intake, watering behavior, and efficiency of use. However, there are currently no data available on these variables related to cattle grazing large pastures greater than 80 ha, while typical pasture sizes in arid regions of the desert southwestern US average over 4000 ha. So far, little has been accomplished in quantifying individual animal variability and efficiency of water intake in rangeland environments. In recent years, a limited amount of studies have attempted to address the genetic influence on water consumption in beef cattle [9; 10; 12]. Nevertheless, the technologies utilized in these studies were limited to confinement situations. In addition to domestic cattle, water consumption by feral animals and wildlife contribute another dynamic to the agroecosystems. Currently, direct quantification of water intake by wild large ungulates [13] or other wildlife species is limited. For example, extant estimates of water consumption by wild ungulates (e.g., Rocky Mountain elk, _Cervus elaphus_) rely on formulas developed for domestic animals [11], are based on confined animals [14], or use indices [15]. Improved knowledge of water requirements for wild animals under variable natural environmental conditions will contribute to wildlife conservation planning significantly. Quantified information on water intake by wildlife will contribute to a debate on the value of anthropogenic water developments for wildlife and the effects of supplemental water in the environment [16; 17; 18; 19; 20; 21].