UTILIZZO DELLA TECNICA TERMOGRAFICA COME SISTEMA NON INVASIVO PER LO STUDIO DEL BENESSERE E DELLO STATO SANITARIO NELLE SPECIE ANIMALI DI INTERESSE ZOOTECNICO E DA AFFEZIONE

Using infrared thermography as a innovative and non-invasive system for the study of well-being and health status in farm animals and pet. The particular interest existing about the development in livestock of a system for measuring temperatures at a distance, is witnessed by several articles in international journals, both on laboratory animals, both on rabbit, sheep and horses (Goodwin 1998 ). In fact stress could induce physiological and behavioral changes, as well as vascular changes in different parts of the body that are reflected in changes in body and skin temperatures. In previous studies, physiological reactions in response to acute stress stimuli were found on tail of rats and in ear of rabbit: there was a decrease in temperature at the level of the tail and paws; on the contrary, the temperature of the eye, head and back is increased. The main problems in measurement of temperatures with current methods, are associated with the difficulty of recording the data without causing additional stress due to the handling of animals by man. The thermographic technique can remotely monitor the temperature distribution of a body and its variations, without interacting with it. In fact, thermography is a telemetric technique, non-invasive, able to determine from a distance the temperature of any surface with high spatial resolution (1 cm to 7 meters) and high thermal sensitivity (0 , 08 ° C), taking advantage of that all objects emit infrared radiation in proportion to its temperature. At now thermography has been applied in the animal field just to assess stress response in some research on rabbits, it is currently used for diagnosis of inflammation in the limbs of horses and seems to be of fundamental importance for the early diagnosis of mastitis. The purpose of this thesis research was the development of a system to check temperature of pet and livestock at distance using the thermographic technique, in order to verify the possibility of obtaining an objective assessment of any conditions of stress and / or discomfort. In the “Centro di Allevamento e Addestramento della Guardia di Finanza, temperatures of 20 dogs were taken at a distance, while behavioral tests were carried out by a team independent from the thermographic technician and according to their defined sequences. We obtained thermographic videos that, in addition to the behavior of the subjects, provides information on the variation in skin temperature during test, in the same dog, and between different subjects. The most suitable areas to detect the temperature changing were defined as the area around the eyes and the inner of ears. These videos are the beginning of the database for the canine species and represent the material of two theses currently in progress at the Department of Animal Sciences - Milan. The availability baseline data on various species is a key to refer to in order to successfully apply this non-invasive technique to assess animal’s well being. No interaction is needed between the operator and thermographic animals, thus confirm the non-invasiveness of the developed system. For the analysis of thermal images obtained, it is still developing, in collaboration with the Physics Department of Milan, a software that can automatically extract the array of temperatures of interested areas identified. Regarding the syndrome of poor performance in sport horses, 9 thermography videos were made during exercise on high-speed treadmill, which made possible to record the heating of the different muscle areas of the body and to verify the proper vascularization of tissue, in addition to identifying abnormal responses caused by diseases and stress. Such studies have been conducted at the Hospital for Large Animals of Lodi and allow to test and enhance the training of sport horses. As far as dairy cows, the thermographic technique is proved particularly useful in the early detection of podalic diseases, allowing early intervention and improving animal welfare; different experimental sessions were conducted at the farm Angelo Menozzi Landriano, in collaboration with DIPAV of University of Milan. Values of sensitivity of 86% and specificity of 63% were obtained using the clinical evaluation as a reference. In collaboration with the Department of Agro-Food Protection and Enhancement of Bologna, 2 long transports of pigs were carried out in north-central Italy to determine whether thermography can be used in the assessment of environmental stress on pigs in the truck during transportations. Thermographic skin temperature measurements were performed for the first time during a transport by a camera placed inside the vehicle. The contemporary environmental conditions checking allowed the determination of a relationship between these two quantities in accordance with the present literature about. About swine, some experimental tests were performed to evaluate the best conditions for breeding and reproduction in collaboration with the Scottish Agricultural College, Edinburgh. Studying on thermoregulation phenomena of nude mice, some experiments were carried out in collaboration with Siena Biotech. Thermography has allowed the identification of an "hot" area in the dorsal area of animals, which coincides with so called “brown fat tissue” and is involved for rodents in thermogenesis. The measurements taken at different days have proved consistent and repeatable, it was possible to define the thermal behavior of brown tissue even under conditions of hypothermia and hyperthermia. Finally, for a better and more automated analysis of thermal images obtained, it is still developing a software specifically for the treatment of the thermal images of moving subjects, in collaboration with Department of Physics - University of Milan.