Influence of environment temperature on the performance and the physiological traits of barrows from 30 to 60 kg

[摘要] - The present work was conducted to evaluate the effect of constant thermal environment on the performance and physiological traits of barrows from 30 to 60 kg LW. A total of 100 animals were allotted to a randomized block design, with five treatments (3100, 3250, 3400, 3550 and 3700 kcal of DE/kg of diet), five replicates and two animals per experimental unit. Weight gain, intakes of diet, protein and energy and feed:gain ratio and the efficiencies of protein and energy utilization were reduced in the heat environment. Fast weight/live weight ratio was higher in the heat environment and the environment temperature did not affect the carcass weight/fast weight ratio. The protein deposition rate increased and the fat deposition rate decreased as the environment temperature increased. The environment temperature reduced the internal organ weight and increased the respiratory frequency, in the animals maintained under heat. Although feed:gain ratio had decreased in the heat environment, the animals maintained in this environment presented higher protein deposition rate in the carcass.

[学科分类] 兽医学

[关键词] thermoneutral;heat stress;growing swine;performance;internal organs;carcass     IntroduçãoA resposta dos suínos ao estresse de calor consiste;principalmente;na intensificação da dissipação de calor por evaporação pelo trato respiratório;seguida da redução no consumo de alimentos;com conseqüente redução na ingestão de energia e na atividade da tireóide;constituindo um esforço do animal em reduzir a produção de calor metabólico (BIANCA;1968; FIALHO;1994)