Development of Tetrapod Zinc Oxide-Based UV Sensor for Precision Livestock Farming and Productivity

In order to ensure the health and welfare of livestock, there has been an emphasis on precision farming of ruminant animals. Monitoring the life index of ruminant animals is of importance for intelligent farming. Here, a wearable sensor for monitoring ultraviolet (UV) radiation is demonstrated to understand the effect of primary and secondary photosensitization on dairy animals. Thin films of wide bandgap semiconductor zinc oxide (ZnO) comprising multilevel of nanostructures from microparticles (MP) to nanoparticles (NP), and tetrapod (T-ZnO), were prepared as the UV sensing active materials. The sensitivity was evaluated by exposing the films to various radiation sources, i.e., 365 nm (UV A), 302 nm (UV B), and 254 nm (UV C), and measuring the electrical resistance change. T-ZnO is found to exhibit higher sensitivity and stable response (on/off) upon exposure to UV A and UV B radiation, which is attributed to their higher surface area, aspect ratio, porosity, and interconnective networks inducing a high density of chemical interaction sites and consequently improved photocurrent generation. A wearable sensor using T-ZnO is packaged and attached to a collar for dynamic monitoring of UV response on ruminant animals (e.g., sheep in this study). The excellent performance of T-ZnO wearable sensors for ruminant animals also holds the potential for a wider range of applications such as residential buildings and public spaces.

PSIV-A-3 Body Temperature Monitoring Using Subcutaneously and Vaginal Sensors in Grazing Cows

Body temperature is an indicator of animal health and can be used to detect harmful physiological events in advance of clinical symptoms. Traditionally, body temperature in cattle is determined with a rectal thermometer and requires the animal to be restrained. Although systems to automatically monitor cattle health in confinement operations exist, assessing the real-time temperature of grazing cows is not common. Our object was to demonstrate an integrated sensor network for monitoring pastured cattle body temperature in comparison with temperature measured by a vaginal logger. The integrated sensor network (Mahindra & Mahindra; Mumbai, India) communicates with the data obtained from a subcutaneous temperature sensor (EmbediVet, Livestock Labs Inc.; Pittsburg, PA) to a cloud-based data storage platform. The vaginal temperature was measured by an implantable temperature logger (Micro-T 16-bit; Star Oddi, Iceland). Vaginal devices were inserted into the vagina using a controlled internal drug release (CIDR) cleaned of progesterone. The subcutaneous temperature sensors were surgically implanted through a 2cm vertical incision in the neck. Data from the implantable sensor were transmitted via Bluetooth communication to a solar-powered base station. The subcutaneous sensors and vaginal loggers were deployed on 10 grazing cattle over a period of 6 months. Data from only 4 subcutaneous sensors consistently reported data. Temperature values measured by the subcutaneous sensors had no statistical relationship (P=0.595) with body temperature measured by the vaginal temperature loggers. However, the subcutaneous sensors were able to detect changes in body temperature over time within-animal, indicating that errors in predicting temperature were more likely due to frameshift issues than an inability to track true temperature. Further improvements in data-processing and higher sample size are needed to maximize the usability of this sensor network for monitoring cattle body temperature.

PSV-A-3 Insulin in Sheep Under Different Patterns of Heat Stress

Livestock welfare and production are readily affected by thermal environment. However, the coordinate physiological shifts associated with heat stress differ substantially when animals have the opportunity to acclimate to thermal environments, or when night cooling occurs. Although some of these responses to thermal environment change have been characterized within some species, physiological signals in sheep associated with gradual versus drastic changes in ambient temperature have not been well studied. The objective of this study was to investigate changes in insulin concentration in sheep exposed to\ thermal environments representing different patterns of temperature change. We hypothesized that insulin would increase in response to rapidly elevated temperature. Six sheep (Suffolk, Dorset, or Suffolk x Dorset, 74.3 ± 13.3 kg) were assigned to 1 of 2 groups exposed to a cross-over experiment. Groups were assigned to 1 of 2 rooms, where they were housed for 20 d, prior to switching rooms. The thermal environment changed five times per period (every 4 d), starting at thermoneutral (20°C, 27°C, 35°C, 27°C, 20°C) in one room and hot (35°C, 27°C, 20°C, 27°C, 35°C) in the other room. Blood samples were collected via jugular venipuncture on day four of each sampling period. Plasma samples were analyzed for concentrations of insulin and glucagon by using a commercial enzyme-linked immunosorbent assay (Ovine Insulin ELISA kit, Eagle Biosciences Inc, #INO91-K01) per manufacturer’s instructions. Relationships were analyzed as a generalized linear model with insulin concentration as the response variable and temperature, room, period, and animal as fixed effects; 2- and 3-way interactions among temperature, room, and period were also evaluated. Insulin concentration ranged from 0.02 to 0.61 ng/mL, and was significantly influenced by animal (P = 0.044) and the interaction (P =0.004) between room and period. The interaction supports the idea that the pattern of heat loading, so more than absolute heat load modulates physiological adaptation to environment in the short-term