Dissipação de energia térmica e desempenho produtivo de galinhas d'angola submetidas a diferentes condições ambientais.

Abstract

The The breeding of guinea fowl is a viable alternative for small rural producers in arid and semi-arid regions, as they are rustic birds and capable of withstanding the climatic adversities of the regions. The objective of the present work was to evaluate thermal changes,11 physiological responses, productive performance and carcass yield of guinea fowl (Numidia meleagris) under conditions of thermoneutrality and thermal stress. The birds were distributed following a completely randomized design, with two treatments (air temperatures) and 4 repetitions (the experimental boxes), with 12 birds each. The increase in air temperature resulted in a significant increase in thermal exchanges in the latent form, physiological responses and water consumption, resulting in the flaps in the sensitive form and a reduction in the weight percentage of the feathers, with no changes in feed consumption, carcass yield and weight gain. The present study demonstrated that the guinea fowl were subjected to severe thermal stress based on the UTI values at a temperature of 32 ° C. With the increase in the air temperature, the birds reduced in half the heat lost to the environment in a sensitive way and increased in more than 80% the heat eliminated in the evaporative form, increasing the physiological responses. Based on the productive data and carcass yield, it is possible to state that the guinea fowl are adapted to environmental conditions of air temperature up to 32 ° C. At the higher air temperature, the birds reduced the percentage of feathers, with no changes in the performance and carcass of the birds. Among the physiological responses, rectal temperature stood out, showing a better correlation and agreement in the exchange of sensitive and latent heat due to the increase in air temperature.