A research was conducted to evaluate the performance of broilers reared in conditions of heat stress, during 1-21 days of age, fed with diets containing different levels of selenium ( 0,5; 1,1; 1,7; 2,3; 2,9 and 3,5ppm of Se.Kg -1 of diet). The experimental diets were isonutritives except for selenium. Sixty chicken strains Ross, mixed, distributed in a randomized block design with six treatments and five replications with two birds per pen were used. The internal environment of the sheds was evaluated based on the Temperature Index Black Globe Humidity (BGT), the Temperature and Humidity Index (THI) and Effective Temperature (ET). The behavioral variables were: eating, drinking , open beak, wing open, stop, lie down, walk, scratching, stretching limbs, bunch of dust, clean feathers, fighting and prostrate. Levels of selenium in the diet interfered in the frequency of visits to the feeder of chickens, with the experimental treatments of 1.7 and 2.3mg Se.Kg -1, presenting lower values. However, the frequency of chickens with behaviors: drinking, with open wings standing, walking, carrying out cleaning of wings, fighting prostrate and were not influenced by the levels of selenium diets. Thus, it can be inferred from the contradictory behavioral results obtained in this study, several factors are involved in the behavior of birds, with emphasis on the environmental and nutritional variables.
broiler growing; ethogram; performance