Disclosed are a system, device and process for monitoring physical and physiological features of livestock through a unique monitoring system and device. Basic and Smart tags are placed on livestock to monitor, among other things, temperature, movement, location, posture, pulse rate, and other physical and physiological features. Information is relayed from Basic tags, in one embodiment, to Smart tags that requests the information and receives the information from the basic tags. Smart tags send information to a mobile unit controller and/or home base so that requested information is sent to an end user that monitors the livestock for signs of illness. Potentially ill animals are segregated from the herd for further evaluation and minimization of exposure risk to the rest of the herd. This early detection system saves livestock and ensures a healthier herd for livestock farmers.