Productive responses from broiler chickens raised in different commercial production systems ? part II: Impact of climate change.

Abstract: Broiler chickens are homoeothermic animals, i.e., animals capable of maintaining their body temperature within quite narrow limits; therefore, climate change poses a great challenge to poultry. With this in mind, this research aims to evaluate the performance of broilers submitted to different commercial production systems and exposed to different future scenarios, taking into account the climate change trends. To achieve this objective, we developed and validated a fuzzy model able to predict the performance of a broiler as a function of enthalpy along its life stages. This model was developed and validated in part I of this article based on experimental data collected for one year in three aviaries: conventional, negative pressure, and dark house systems. A Mann?Kendall nonparametric test and linear regression analysis were applied to the enthalpy values, which were calculated as a function of the ambient air temperature and relative humidity in order to study the climate change trends. Later, simulations were performed using the fuzzy model for 2025, 2050, 2075, and 2100 future scenarios. Specific improvements were observed when the heating trends coincided with the initial stages of breeding; however, in general, the productive responses of broilers in the different evaluated systems worsened with the climate change trends. Faced with the climate change trends, the responses improved in the order dark house aviary > negative pressure aviary> conventional aviary