Determinação das faixas de conforto térmico para frangos de corte de diferentes idades criados no Brasil

• Autor(a) principal: Cassuce, Déborah Cunha
• Data de Publicação: 2011
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/704
• topic: Avicultura; Ambiência; Aviculture; ambience; CNPQ::CIENCIAS AGRARIAS::ENGENHARIA AGRICOLA

The comfort thermal levels inside the poultry installations is a very important factor to determinate the activity success in poult meat production. The excess in cold or warmth temperature is reverted in low productivity in poultry, affecting their general performance and their health, could occurring extremes situations, as the allotments increase mortality. Therefore, become much relevant to know the thermal level considered comfortable and adequate to the high poult meat production performance in different stages. However, it‟s believe that the temperatures range currently establish as great by the poultry lineage standard could be lagged because the nutrition and genetic changed, as the birds acclimatization in Brazil‟s weather. In view of the exposed, was realized this research, with the aim in evaluate and establish the rang really representative of the thermal comfort to different ages in poultry acclimated in Brazilian conditions, as the different temperatures influence in cold or warmth stress in creation initial stage (poult heat period) on the final performance in birds submitted to the comfort or different conditions in caloric stress situation that happens almost invariably in natural conditions in Brazil). To this, the field work was realized in five chamber climate situated in AMBIAGRO - DEA/UFV, with male poult of COBB linage, being conducted in two stages: first stage with 600 birds in 1 to 21 days and second stage with 240 birds in 21 to 42 days. In the first stage was identify the influence in five different ambient thermal conditions, on performance, physiology and birds behavior in 1 to 21 days, constituted as five treatments: thermal comfort recommended by literature to the three firsts weeks in the birds life (33, 30, 27°C, respectively), two level in cold stress (30, 27, 24°C e 27, 24, 21°C), as the influence in this different treatments in the first stage on the general behavior to the final in the creation period. In the second stage experimental, the birds redistributed in the way that poult in each one of the five treatments of first stage were submitted to a situation in thermal comfort recommended (23°C) and in two heat stress level (27 e 31°C) during 12 hours per day, constituted, in this way, 15 new treatments. During the night period, all birds were kept in comfort thermal ambient. Were analyzed parameters in the animal performance (weight gain, ration and water consume, food conversion, corporal weight and carcass income), physiologic (rectal and surface temperature, T3 and T4 hormone concentrations in blood plasma and the viscera relative weight) and behavior aspects too (as the stress demonstrations, space distribution and feeder and drinker presence). In general, the birds kept in 30, 27 and 24°C temperature, known by literature as caused stress by cold, during three first weeks in their lives, respectively, presented better performance that one expose to the most situations, indicating that these would be the ambient temperature desirable to the poultry creation in initial stage. In the same way, when submitted to the thermal comfort recommended during the second stage of life, these birds maintained better performance that those original from the others treatments, including those that kept in recommended as being thermal comfort in all experimental period. As base the regression analyze of the performance result, ITGU, behavior and physiologic, concluded that the comfort temperature to poult in the first three weeks in their lives were 31,3ºC in the first week, between 26,3 and 27,1ºC in the second week and between 22,5 and 23,2 ºC in the third week, and the temperature that the bird is expose in the first stage in life echoes in the allotment final performance.