Sistema de produção de frangos de corte caipira com piquetes enriquecidos e sua influência no bem-estar animal e desempenho zootécnico

Abstract

This study was conducted to evaluate the effect of an enriched environment on the production system of free range rustic broilers. The influence of meteorological conditions was studied in terms of thermal comfort, physiological parameters and behavioral responses of the broilers. The most favorable conditions for growth were verified based on the indications of welI-being as a response to the rearing environment. The experiment was performed during a production cycle of 87 days in the city of Carpina, State of Pernambuco, at the Experimental Station of Small Animais of the University Federal Rural of Pernambuco (UFRPE). The research was conducted in four production modules divided into four boxes with 10 birds per box, totaling 160 birds, subject to the four modules of production: access to paddock (Ti), with access to paddock with perch (T2), with access to paddock with artificial shade (T3), and with access to paddock with perch and artificial shade (T4). The work was divided into three stages depending on the type of assessment data: bioclimatic analysis, behavioral analysis and analysis of the performance of the birds. The bioclimatic analysis was performed using the dry bulb temperature (Tbs; °C), the wet bulb temperature (Tbu; °C), the black globe temperature (Tg; °C) and wind speed (mis) registered in the production modules and in the external environment which allowed the establishment of the thermal efficiency using the globe temperature and humidity index (ITGU), radiant thermal load (CTR), enthalpy (h), and the physiological parameters: respiratory rate, comb temperature (°C), wattle temperature (°C) and thigh temperature (°C). Six birds from each rearing4 system were randomly selected to evaluate their behavior, totaling 24 birds consisting of 3 birds per box, with two replications in each production module. The observations were made between 7 - 8 a.m., 10 - 11 a.m., 1 - 2 p.m., 4 - 5 p.m. Their behavior was registered every 5 minutes. The analysis of the performance of the birds had varying responses in terms of feed intake (FI); weight gain (WG); feed conversion FC; live weight (LW) and yield of carcass and cuts. The experimental design was completely randomized into subdivisions. The weeks were allocated to the plots and the production modules were allocated to the subplots. The averages were compared using the Tukey test. The meteorological variables and the comfort indices indicate that the production module with access to the paddock with perch and artificial shade offered the birds the best thermal comfort having an average enthalpy value of 75.95 kJ/kg. The physiological parameters: respiratory rate (mov.Imin.), comb temperature (°C), wattle temperature (°C) and thigh temperature (°C), showed better values in terms of lower heat stress in birds in the (T4) production module. The birds in the production module with access to paddock with perch and artificial shade (T4) were those that had better opportunity to express their natural behaviors and to explore the environment outside the production module thus increasing their weII-being in response to the enriched environment. The production modules (T2) and (T4) showed the best performance with average yields of 2.53; 2.54 kg / bird; 2.54; 2.57 kg / bird; 7.51; 7.6 Mcal / bird and 3.22; 3.24 kg / bird, in terms of weight gain, feed conversion, energy consumption and live weight, respectively. The production modules did not promote significant changes in the yield of the free range rustic broilers.