R ESU M ONeste trabalho objetivou-se avaliar os índices bioclimáticos que influenciam as varáveis fisiológicas, desempenho e consumo de nutrientes de tourinhos das raças Gir e Guzerá. O estudo foi realizado na Estação Experimental de Alagoinha/EMEPA-PB, no município de Alagoinha, no agreste paraibano, Brasil, utilizando-se 16 tourinhos das raças Sindi e Guzerá (8 animais de cada raça), com média de 31,5 ± 1,5 meses de idade, mantidos confinados. O delineamento estatístico utilizado foi o de blocos inteiramente casualizados, com 8 repetições, em parcelas subdivididas, com raça na parcela principal e horários (6, 12 e 16 h) na subparcela. A temperatura retal, frequência respiratória e temperatura superficial dos animais se mantiveram dentro da faixa considerada normal para a espécie bovina. Não houve influência negativa no consumo de nutrientes e os animais tiveram um desempenho em ganho de peso acima do esperado, demonstrando que estão adaptados às condições de Nordeste brasileiro, já que não houve alterações em seus parâmetros fisiológicos, considerados dentro da faixa normal e ainda apresentaram excelente desempenho produtivo e de consumo de nutrientes.Palavras-chave: adaptabilidade, ambiência, desempenho produtivo Thermoregulation and performance of Sind and Guzera young bulls in 'Agreste' region of Paraiba State A B ST R A C T The objective of this study was to evaluate the bioclimatic indices that influence physiological variables, performance and nutrient intake by Gir and Guzera young bulls. The work was conducted at the Experimental Station of Alagoinha/EMEPA-PB in Alagoinha town in 'Agreste' region of Paraiba state, Brazil, using 16 young bulls of Sind and Guzera breeds (8 animals of each breed), with a mean 31.5 ± 1.5 months of age, kept under confined conditions. The statistical design used was randomized blocks with eight replications in split plot with breed in the main plot and time (6, 12 and 16 h) as subplots. Rectal temperature, respiratory rate and surface temperature of the animals remained within the normal range for the bovine species. There was no negative influence on food intake and the animals had weight gain higher than expected, demonstrating that they are adapted to the conditions of northeastern Brazil, since there were no changes in their physiological parameters considered within the normal range and still showed excellent growth performance and nutrient intake.

ABSTRACT:The objective of this study was to evaluate the quality of air, bioclimatic indexes of facilities and physiological indices of Guzera and Sindhi calves, reared in climatic conditions of Agreste. The study was conducted at the experimental station of Alagoinha, PB, Brazil, using 16 calves of Sindi and Guzerá races. The average concentration of oxygen (20.85%), ammonia (1.99 ppm), carbon monoxide (<0.01 ppm), methane (0.13 ppm) and hydrogen sulfide (<0.01) within facilities, were within the limits established by the Brazilian and international standards, for both animals and workers. The bioclimatic index of temperature and humidity and the temperature of the black globe and humidity index were within the thermal comfort zone for cattle in most of the experimental period, the mean values of respiratory frequency (26.0 min mov -1 ) and skin temperature (32.3 °C) were higher in the hottest time of the day (1 pm) and rectal temperature (39.3 o C) in the late afternoon (5 pm), but remained within normal ranges for the studied races. The races have good adaptability to climatic conditions in the region of the Paraibano Agreste, Brazil.