Advances in Poultry Welfare

Joy Mench

• Publisher: Woodhead Publishing
• Year: 2017
• Print ISBN: 9780081009154
• eBook ISBN: 9780081009307
• Topic: Technology & Engineering
• Subtopic: Zoology
• Index: Technology & Engineering

Advances in Poultry Welfare provides a targeted overview of contemporary developments in poultry welfare. The reviews in the volume address topical issues related to poultry welfare research and assessment, with a focus on identifying practical strategies for improvement as well as information gaps that remain to be filled.Part One provides an introduction to poultry production systems and gives a broad overview of current poultry welfare issues. Part Two moves on to review several aspects of poultry management, focusing on hatchery practices, early rearing, and slaughter. Part Three deals with welfare assessment on the farm, while Part Four explores continuing challenges, such as feather pecking and skeletal problems. This is followed in Part Five by a discussion of emerging issues, with chapters covering alternative parasite control methods, backyard poultry production, mass depopulation, and genetic approaches to reducing the impact of environmental stressors on welfare.This book is an essential part of the wider ranging series Advances in Farm Animal Welfare, with coverage of cattle, sheep, pigs, and poultry.With its expert editor and international team of contributors, Advances in Poultry Welfare is a key reference tool for welfare research scientists and students, veterinarians involved in welfare assessment, and indeed anyone with a professional interest in the welfare of poultry.- Provides in-depth reviews of emerging topics, research and applications in poultry welfare- Integral part of a wider series, Advances in Agricultural Animal Welfare, which will provide comprehensive coverage of animal welfare of the world's major farmed animals- Covers a range of topical issues within the field, from beak-trimming and skeletal problems, to early rearing and the design and management of poultry production systems- Edited by a distinguished leader in the field

Part I

Introduction

Outline

1 Overview of commercial poultry production systems and their main welfare challenges

1

Overview of commercial poultry production systems and their main welfare challenges

Darrin M. Karcher¹ and Joy A. Mench², ¹Purdue University, West Lafayette, IN, United States, ²University of California, Davis, CA, United States

Abstract

Commercial poultry production has changed since the 1950s. Genetic selection has resulted in two different types of commercial poultry, meat and egg-laying birds. Production systems for meat birds (chickens, turkeys, and ducks) are similar in their configuration and management, although there are some differences due to the species being grown and the desired days to market. In contrast, the table-egg industry is changing rapidly due to animal welfare concerns, particularly in developing countries, and egg-laying hens are now produced in a multitude of systems requiring different types of management expertise. We provide an overview of the commercial production systems commonly used for rearing meat birds and egg-laying hens. We also identify some of the major welfare challenges related to health and behavior within current systems, and discuss emerging consumer preferences that will shape poultry production systems, and their associated welfare concerns, in the near future.

Keywords

Turkeys; ducks; broilers; laying hens; pullets; housing system; welfare; health; behavior

1.1 Introduction

Commercial poultry production practices have changed dramatically since the 1950s. Most commercial poultry are now raised entirely indoors, in environmentally or semi-environmentally controlled buildings. They are managed to maximize production, for example by feeding diets that are formulated for their nutritional needs at various stages of the rearing or egg-laying cycle and by providing controlled photoperiods and light intensities to stimulate growth or egg laying. A major source of change has been the intense genetic selection for either growth or egg laying, leading to the development of two different types of poultry—meat birds and table-egg layers—which are managed by two separate sectors of the poultry industry.

As a result of these factors as well as advances such as better prevention and control of disease via vaccines and antibiotics, the poultry industry has grown significantly over the last few decades, with the consumption of both poultry meat and eggs increasing globally, an increase that is predicted to continue, particularly in developing countries (NRC, 2015). Although many different species of poultry are grown around the world for meat and eggs, the three primary species produced commercially are chickens (for meat and table eggs), ducks (mainly Pekin ducks for meat), and turkeys (for meat).

As production has grown and intensified, so too have concerns about animal welfare. As early as 1965, the influential U.K. Brambell Committee “Report of the Technical Committee to Enquire into the Welfare of Animals Kept under Intensive Livestock Husbandry Systems” identified a number of potential welfare issues in commercial poultry production, including beak trimming (which they suggested might cause pain), the restriction of space and behavior in conventional cages for hens, risks of disease and cannibalism in loose housing systems for hens, the use of dim lighting for both meat chickens and laying hens, high stocking densities for broiler chickens and turkeys, and the potential for mechanical failure in automated housing systems (Brambell, 1965). Most of these concerns persist, and others have emerged as commercial production systems have evolved and public interest in animal welfare has continued to intensify, particularly in developed countries.

In this chapter we describe the main systems used for rearing commercial meat and egg-laying chickens, Pekin ducks, and turkeys, and give a short overview of the key welfare issues. The focus is mainly on production systems in the United States, but similar systems are used in many other countries although they may be managed somewhat differently due to local differences in legislation, standards, availability or cost of resources (for example litter or feedstuffs), or markets. We note that, in the United States, there are no federal laws that regulate the animal welfare aspects of housing systems or production practices for poultry aside from the provisions included in the standards of the National Organic Program. Instead many producers follow voluntary animal welfare standards established by their industry trade organizations, and/or those of independent (third-party) certifiers (e.g., retailers, animal welfare labeling programs). Although the main focus of this chapter is on rearing and production systems for meat and egg-laying poultry, we briefly address some of the welfare concerns associated with breeding, hatcheries, and loading and transport. Detailed information about the welfare aspects of slaughter, euthanasia, and mass depopulation of poultry (when there is a serious disease outbreak, for example) can be found elsewhere in this volume (Lambooij and Hindle, Chapter 4; Linares et al., Chapter 7; McKeegan, Chapter 17; Vizzier-Thaxton, Chapter 5).

1.2 Meat birds

1.2.1 General aspects of housing and management

The rearing systems for broilers, turkeys, and ducks are quite similar. In general, meat bird production systems involve rearing birds indoors on a litter floor. The litter is typically wood shavings-based but straw, sand, rice hulls, and other materials may be used. Houses average 20,000 ft² (1858.1 m²) in area but stocking density varies depending on the type of meat bird being raised. The birds are placed in the house on the day of hatch (started) and provided with supplementary heat during the brooding phase, which may involve confining them to a portion of the house until they are better able to regulate their own body temperature. Automated drinkers and auger feed lines are used to deliver feed and water. Diets are phase fed, which allows for the requirements of the growing birds to be met during the different production phases.

Houses may have either tunnel ventilation or natural ventilation; in the United States, ventilation type depends on geographic location of the farm. Tunnel ventilation pulls the air through the house using inlets and exhaust fans while natural ventilation utilizes open-sided houses with curtains to control the amount of air flow. Lighting programs typically provide 23:1 light:dark for the first 7 days and then 20:4 for the remainder of the production period. However, there are many different kinds of lighting programs and the way the light is provided (e.g., lighting type, intensity, and long or intermittent blocks of light) can vary from one farm to another, and according to whether producers are following particular standards. Daily care entails walking the house at least once per day to collect mortality, identify health issues (Linares et al., Chapter 7), verify that feed, water lines, and other equipment (e.g., ventilation) are working appropriately, and check litter condition.

After the birds are sent to the processing plant, the producer prepares the house for another flock of birds. At a minimum this requires cleaning the feed and water lines, as well as removing large aggregates of litter and redistributing and conditioning the remaining litter in the house. For biosecurity reasons related to disease prevention, producers usually wait for 10 to 21 days before placing a new flock in the house. Some countries and certification programs have more stringent requirements for house preparation, for example, requirements to remove and replace all litter or to follow particular cleaning and disinfection protocols between flocks.

Below, we present an overview of the intensive systems that are the ones most commonly used for the commercial production of meat chickens, turkeys, and ducks. However, there is a small but growing segment of the industry in developed countries that raises meat birds in systems that range from semi-intensive to extensive. These include systems that provide the birds with outdoor access once they are past the brooding period (free-range) and systems where the birds are raised primarily outdoors (pasture-based systems or pond-based systems for ducks). Either free-range or pastured systems can be used for organic production, as long as they meet legal requirements (e.g., related to provision of organic feedstuffs and restrictions on the use of particular compounds for the prevention or treatment of disease). These systems tend to be quite variable in terms of their management and configuration, and producers may use atypical breeds, like Heritage breeds, that are better suited for outdoor rearing than typical commercial breeds or strains. Because of their variability, we will not attempt to describe these systems here, although some mention is made later about welfare concerns related to outdoor access for both meat and egg-laying birds, as well as organic production.

1.2.2 Broilers (meat chickens)

The USDA Agricultural Marketing Service defines four classes of meat chickens (Cornish game hen, Rock Cornish fryer or roaster, broiler or fryer, roaster) based on age, extent of keel bone (breastbone) calcification, and genetic stock (AMS, 2002). The industry, however, defines classes based on the size of the bird marketed (“small” to “big”), with days to market varying between 33 and 64 for the different sizes of birds. The difference in days to market is based on the final disposition of the carcass, i.e., as a whole bird, parts, or for the fast food or further processed product markets. Female and male chicks are usually raised together (referred to as straight-run rearing), but may sometimes be raised in separate houses (sex-separate). Fig. 1.1 shows a typical commercial broiler house during both the early and late rearing stages.

Figure 1.1 (A) Broiler chicks in a conventional house with alternating feed and water lines. Notice the plastic curtain in the background dividing the house to create a brooding area initially. (B) Broiler chickens close to market age in a tunnel ventilated production house.

In the United States, the standards of the National Chicken Council (NCC), which is the trade organization for broiler producers, recommend stocking densities varying from 6.5 to 9.0 pounds of live weight per 1 ft² (929 cm²) of house floor area (31.7–43.9 kg/m²) depending upon the desired market weight of the birds (NCC, 2017), whereas the European Union (EU) standards specify a range from 6.8 to 8.0 lbs/ft² (33–39 kg/m²) depending not only on bird size but on other aspects of management related to house air quality and thermal control (CEC, 2007). Daytime light intensities after the first week of the rearing period are typically kept very low, often less than 5 lx in the United States, although higher intensities are required in some countries (e.g., in the EU, where a minimum of 20 lx is required over 80% of the house throughout most of the production period) and for some certification programs. Drinking water is typically provided via nipple drinkers to help maintain the litter in dry condition.

When the birds are ready for market, the feed and water lines are hoisted to the ceiling, eliminating obstacles for the catch crew. Broilers can be caught by hand or by machine (e.g., chicken harvester or catching machine). With hand catching, the catch crew enters the broiler house and corrals the birds into a catching area. Transport containers are brought into the house and the crew hand-catches the birds and places them into the transport coops (crates). When each bank of coops is filled, it is placed onto the transport truck. If a catching machine is used, an individual controls the machine as it moves through the house. The machine uses a system of belts to move the broilers from the floor of the house to the transport coops. Each individual bird is weighed and when the desired total bird weight is reached for a particular coop, the belt is moved to the next coop. The number of broilers placed into each coop is...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• List of contributors
• Preface
• Introduction: Topical issues in poultry welfare
• Part I: Introduction
• Part II: Management: Hatch to slaughter
• Part III: Welfare assessment on the farm
• Part IV: Continuing challenges
• Part V: Emerging issues
• Index