Infrared Thermography and Metabolic Changes in Castrated Piglets due to the Effects of Age and the Number of Incisions in the Testicles

The objective of the study was to evaluate infrared temperature and metabolic responses in different-aged piglets castrated surgically with one or two incisions. The piglets were divided into groups according to age (5- and 13-day old) and the number of incisions: simulated castration; castration with one incision (C1I5 and C1I13); and castration via two incisions (C2I5 and C2I13). Temperature evaluations were performed with an infrared thermal thermography camera in the eyes, the thorax and the scrotal area, at 24 h before castration (RV), immediately after castration (PC), 24 and 48 h post-surgery. The study also evaluated plasma glucose and lactate concentrations. The thorax presented lower infrared temperature in the groups C1I13 and C2I13 than those in C1I5 and C2I5 (p<0.05). Regardless of age and type of castration, plasma lactate values increased PC (P=0.0001). The piglets castrated at 5 days of age were less susceptible to presenting temperature changes regardless of the number of incisions, while the animals castrated at 13 days with two incisions showed lower temperatures and imbalances in plasma glucose and lactate concentrations. Castration in piglets of 13 days causes a decrease in temperature in the lacrimal caruncle immediately after performing surgery. The physiological responses caused by castration are less marked in 5-day-old piglets.