USE OF PROTECTION SCREEN IN CONVENTIONAL AVIARIES (CALIFORNIAN TYPE) FOR LAYING HENS

Dian Lourençoni,Daniela D De Oliveira,Mariela R Da S Pena,Renato R De Lima,Tadayuki Yanagi Junior

doi:10.1590/1809-4430-eng.agric.v39n1p48-54/2019

Abstract

ABSTRACT The objective of this work was to evaluate the thermal environment inside conventional cages for laying hens, with and without the use of protective screens. This research was conducted in two conventional cages (open cage), where each cage had half of its area surrounded by high density polyethylene mesh (HDPE) with a diameter of 2.0 cm, and the other half was kept fully open. Hyline W-36 and Dekalb Brown laying hens were housed in these cages. The wind speed, dry bulb temperature (tdb), black globe temperature, humidity index (BGHI), and enthalpy (H) were analyzed. The results indicate that the use of the screen reduced the wind speed inside the cage by 0.22 m s−1. The presence of the screen affected tdb, BGHI, and H in some of the evaluated periods evaluated, making these values higher than those of the treatment without screen. However, the obtained values are within or below the thermal comfort range for laying birds. Therefore, the use of HDPE screen in the cages altered their internal environment. However, it is not enough to hinder the thermal comfort of the housed animals.

Highlights

Owing to the occurrence of avian influenza viruses (H5N1 and H7N2), several studies related to avian biosafety have been conducted
No studies regarding the influence of using protective screens on the thermal environment of conventional cages for commercial laying hens were found in the literature
The protection screen used to cover a part of the cage was made of black-colored high-density polyethylene (HDPE), with a mesh of 2.0 cm diameter, which is compliant with Normative Instruction No56 (MAPA, 2007)

Summary

Introduction

Owing to the occurrence of avian influenza viruses (H5N1 and H7N2), several studies related to avian biosafety have been conducted. According to article 14 of Normative Instruction No 56 (MAPA, 2007), superseded by Normative Instruction No 36 of 2012 (MAPA, 2012), all commercial poultry establishments, in addition to other specifications, must be provided with protection to the external environment, with the installation of screens with a mesh size not greater than 2.54 cm (1.0 inch) to prevent the access of birds, domestic animals, and wild animals. No studies regarding the influence of using protective screens on the thermal environment of conventional cages for commercial laying hens were found in the literature. Depending on the screen material, wire thickness, and mesh size, the air flow inside the cage may be reduced, increasing the thermal discomfort of the birds owing to the reduction of thermal changes between the internal and external environment

Objectives

Methods

Results

Conclusion