Performance of free-range chickens reared in production modules enriched with shade net and perches

Mjb Santos,Ep Silva,Pa Santos,Tr Torres,Wb Morril,H Pandorfi,Cbv Rabello,Nm Duarte

doi:10.1590/s1516-635x2014000100003

Mjb Santos, Ep Silva + Show 6 more

Open Access

https://doi.org/10.1590/s1516-635x2014000100003

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Abstract

An experiment was carried out to evaluate the effect of environmental enrichment in a free-range chicken production system on live performance as a function of microclimate, physiological parameters, and performance parameters. Four production modules were divided into four pens with 10 birds each, totaling 60 birds. The following treatments were applied: access to a paddock (TEST), access to a paddock with perches (PER), access to a paddock with artificial shade (SHA), and access to the paddock with perches and artificial shade (PESH). The PESH production module presented the best globe temperature (Tbg,ºC) and enthalpy (h, kJ/kg), and thereby, the best thermal environmental conditions, which ensured the longest permanence time of the birds in the paddock. The SHA and PESH modules promoted the lowest respiratory rate and shank and comb temperatures. Live performance was influenced by the presence of environmental enrichment (modules SHA and PESH), with the highest live weight (LW) and weight gain (WG) and the lowest feed conversion ratio (FCR) and metabolizable energy intake (MEI). Parts yield, such as giblets, were not influenced by production modules, except for PESH, which promoted higher offal weight. In general, chickens reared in enriched production modules presented greatest performance and comfort results and were considered close to optimal rearing conditions.

Highlights

Animal welfare has been in the forefront of the international debate on animal production over the last decade, especially in the European Union
The highest temperature was recorded in the module with no environmental enrichment (TEST), as it had no means to reduce the internal temperature as in the module with perch and artificial shade (PESH) as shown in Table 2, with more than 1oC difference between the treatments were applied: access to a paddock (TEST) and the PESH modules
Production modules and external environment influenced black globe temperature (Tbg), which was higher in the TEST and PER modules compared with SHA and PESH modules, whereas the external environment (EXT) presented the lowest value during the analyzed period

Summary

Introduction

Animal welfare has been in the forefront of the international debate on animal production over the last decade, especially in the European Union. The need for low-cost animal products has led poultry companies to apply rearing practices that increase broiler efficiency without considering their welfare, including thermal comfort and air quality aspects, which poses health, economic, and biosecurity risks. Nääs & Curto (2001) reported that air quality inside and around commercial broiler houses is directly related with health and environmental stressors. In semi-intensive rearing systems, there are less excreta inside the broiler house, reducing pollution and the contact of birds with the excreta. Genetic selection for fast growth has had negative effects on broiler welfare, such as metabolic disorders that may cause ascitis and sudden death (Bessei, 2006). Broiler production has become the focus of many animal welfare studies

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