The Sequential Behavior Pattern Analysis of Broiler Chickens Exposed to Heat Stress

Tatiane Branco,Nilsa Duarte Da Silva Lima,Irenilza De Alencar Nääs,Daniella Jorge De Moura,Stanley Robson De Medeiros Oliveira,Daniela Regina Klein

doi:10.3390/agriengineering3030030

Abstract

Broiler productivity is dependent on a range of variables; among them, the rearing environment is a significant factor for proper well-being and productivity. Behavior indicates the bird’s initial response to an adverse environment and is capable of providing an indicator of well-being in real-time. The present study aims to identify and characterize the sequential pattern of broilers’ behavior when exposed to thermoneutral conditions (TNZ) and thermal stress (HS) by constant heat. The research was carried out in a climatic chamber with 18 broilers under thermoneutral conditions and heat stress for three consecutive days (at three different ages). The behavior database was first analyzed using one-way ANOVA, Tukey test by age, and Boxplot graphs, and then the sequence of the behaviors was evaluated using the generalized sequential pattern (GSP) algorithm. We were able to predict behavioral patterns at the different temperatures assessed from the behavioral sequences. Birds in HS were prostrate, identified by the shorter behavioral sequence, such as the {Lying down, Eating} pattern, unlike TNZ ({Lying down, Walking, Drinking, Walking, Lying down}), which indicates a tendency to increase behaviors (feeding and locomotor activities) that guarantee the better welfare of the birds. The sequence of behaviors ‘Lying down’ followed by ‘Lying laterally’ occurred only in HS, which represents a stressful thermal environment for the bird. Using the pattern mining sequences approach, we were able to identify temporal relationships between thermal stress and broiler behavior, confirming the need for further studies on the use of temporal behavior sequences in environmental controllers.

Highlights

Previous studies show that monitoring the behavior of broilers might provide real-time information on thermal comfort in response to exposure to different thermal environments [1,5–8], since the animal is used as a biosensor [9,10], becoming a valuable noninvasive tool for environmental analysis [11]
We found that, during heat stress, broilers were lying on their side at all ages (p < 0.001), and this is a behavior related to thermal stress
Data mining is becoming more popular in the poultry industry to analyze the constant and vast data sets generated by the increasing use of sensors in the current poultry industry [18,19,35–38]

Summary

Introduction

Extreme weather events are responsible for considerable losses in agriculture worldwide. In countries located in topical and intertropical zones such as Brazil, climate change is increasingly visible. With forecasts of high average air temperatures, climate changes, and heatwaves capable of causing substantial losses in broiler production [1,2], the management of the internal environment in poultry broiler chicken is a critical factor in maintaining the bird’s well-being and productivity, as it cannot move in search of better rearing environmental conditions. Previous studies show that monitoring the behavior of broilers might provide real-time information on thermal comfort in response to exposure to different thermal environments [1,5–8], since the animal is used as a biosensor [9,10], becoming a valuable noninvasive tool for environmental analysis [11]. Behavioral changes can occur quickly and AgriEngineering 2021, 3, 447–457.

Methods

Discussion

Conclusion