LAUSR

ABSTRACT This study aimed to evaluate the influence of dietary supplementation of organic selenium (Se) in non-lactating goats, as well as possible changes in the physiological responses of thermoregulation and in blood constituents under semiarid conditions. The study was undertaken for 42 consecutive days using 22 animals. Data were collected: (1) meteorological, (2) physiological and (3) haematological. The respiratory rate, rectal temperature, epidermis temperature and surface temperature of the pelt presented decreasing values from day zero to the 42nd day of evaluation, with the highest reduction in animals supplemented with Se. For haematological values, it was observed that the values of packet cell volume and mean corpuscular volume decreased significantly (p < 0.05) on the 42nd day of the experiment. For the animals that received dietary supplementation, it is possible to identify a greater association with factor 1, some haematological variables, and for factor 2, some physiological traits were also highlighted. The addition of Se in the diet reduced endogenous heat by reducing respiratory thermolysis and the superficial temperatures of the skin and epidermis, improving sensible and latent heat dissipation and keeping the rectal temperature within normal limits. Abbreviations: RR: respiratory rate; RT: rectal temperature; CT: coat surface temperature; ET: epidermis temperature; RH: relative humidity; AT: air temperature; RHL: radiant heat load; BGHI: black globe humidity index, PCV: packet cell volume; HC: haemoglobin concentration; MCV: mean cell volume; MCH: mean cell haemoglobin; MCHC: mean cell haemoglobin concentration; WBC: white blood cell count; RBC: red blood cell; PCA: principal component analysis.