Changes in Stress Indicators of Egg-Type Chickens in Response to Different Intensive Housing Systems in Humid Tropics

Olufemi Alabi,Banwo Alabi,Daniel Afolabi,Foluke Aderemi

doi:10.5539/jas.v6n4p151

Abstract

Welfare of the animals is of global interest recently and housing of egg-type chickens inside battery cages is being banned in many developed countries in view of the stress to which the chickens are exposed. Measurement of some blood parameters such as White blood cell (WBC) counts and differential leucocytes counts and Heterophil to lymphocyte ratio have been used to assess stress among chickens. Changes in these parameters were therefore investigated among chickens in different housing systems in a typical humid tropical region of the world where animal welfare issue is currently unpopular.108, 17-weeks old Super Black hens (SBL) and 108, 17-weeks old Super Brown hens (SBR) were randomly allotted to three different intensive housing systems of Partitioned Battery Cage (PBC), Extended Battery Cage (EBC) and Deep Litter System (DLS) in a Randomized Complete Block (RCB) design with 36 hens per housing system each with three replicates. The experiment lasted 37 weeks. Parameters measured included Total White Blood cells (WBC), Differential Leukocytes while Heterophil-Lymphocytes ratios (H/L) were calculated .Data collected were subjected to statistical analysis using 2-way ANOVA while means were separated with Duncan’s Multiple Range Test (DMRT). Housing systems had significant effect on the differential leukocyte counts and H/L ratios but not on WBC counts. Hens housed inside PBC (control) had the highest values of H/L ratio with the least values from those housed on DLS. Meanwhile, the parameters investigated were not significantly affected by the strain. Higher values of H/L ratio recorded by hens housed on PBC which is the conventional system of housing layers in the tropics are indications of stress on the chickens due to lack of freedom to move about and which is against the welfare of the chickens.

Highlights

In spite of the global needs to ensure food security for the ever growing population especially in the tropical and subtropical regions, animal production becomes an inevitable source of protein in human diet
Measurement of some blood parameters such as White blood cell (WBC) counts and differential leucocytes counts and Heterophil to lymphocyte ratio have been used to assess stress among chickens. Changes in these parameters were investigated among chickens in different housing systems in a typical humid tropical region of the world where animal welfare issue is currently unpopular.108, 17-weeks old Super Black hens (SBL) and 108, 17-weeks old Super Brown hens (SBR) were randomly allotted to three different intensive housing systems of Partitioned Battery Cage (PBC), Extended Battery Cage (EBC) and Deep Litter System (DLS) in a Randomized Complete Block (RCB) design with 36 hens per housing system each with three replicates
Parameters measured included Total White Blood cells (WBC), Differential Leukocytes while Heterophil-Lymphocytes ratios (H/L) were calculated .Data collected were subjected to statistical analysis using 2-way ANOVA while means were separated with Duncan’s Multiple Range Test (DMRT)

Summary

Introduction

In spite of the global needs to ensure food security for the ever growing population especially in the tropical and subtropical regions, animal production becomes an inevitable source of protein in human diet. Poultry farming is being widely accepted globally of recent with no restriction as a source of livelihood to the rural sector and employment generation for the upcoming youths and it is of paramount importance (Hasnath, 2002).Performance of laying chickens in terms of egg production, egg qualities and livability is a function of breed, environment and the general routine management practices (Campbell & Lasley, 1975; Smith, 1995; Alabi et al, 2006), the environmental photoperiods, wind speed and housing Intensive housing systems such as deep litter and battery cages are commonly used globally. Animal welfare is an important issue on the European Union agenda (Meghan, 2007), and several countries have been coming up with legislation meant to respond to welfare of the animal (Weibe & Jupe, 2005)

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Conclusion