Lecture 7: Poultry and Small Livestock Husbandry

Part 1 (20 minutes): Basic Understanding — What is important and why?

Objective:

In this section we learn what needs laying hens, broilers and sheep and goats have in general and why outdoor access, natural pecking/searching behavior and the density at which animals are kept are important for their well-being. We rely on applicable law and internationally recognized recommendations that describe minimum requirements for housing systems (EU law, German Animal Welfare Act, recommendations of the international animal health organization WOAH/OIE).

Let us begin with a simple picture: imagine a class of students crammed into a single, too-small classroom without space to move, without a playground and without places to withdraw. After some time stress, conflicts and health problems arise. Animals react similarly when they lack space, the opportunity to express species-typical behaviors, or resting places. For laying hens this includes, for example, pecking and scratching, nesting and sitting on perches; for broilers (meat chickens) movement, air space and an appropriate density are important; sheep live in groups and need pasture access and protection from the weather; goats are curious and like to climb.

Outdoor access does not only mean that animals are let outside. For hens, outdoor access additionally enables extra foraging and exploratory behavior, sunlight and fresh air; for sheep and goats pasture access means access to natural feed, exercise and social contact. Stocking density — how many animals per area — directly affects hygiene, air quality, stress levels and the occurrence of diseases as well as behavioral disorders. From this it follows: housing system, management and the provision of suitable equipment are decisive for animal welfare. Legal regulations at the EU level and national laws set minimum requirements, such as equipment requirements for laying hens or controls for broiler production.

Part 2 (20 minutes): Technical Terms and In-Depth Explanations

Objective:

In this section we introduce central technical terms, explain their meaning and link them to legal and practical requirements.

Pecking behavior: Pecking refers to the targeted taking of feed or objects with the beak. In hens, pecking is a natural foraging behavior that also has social aspects. If animals do not have sufficient occupation, suitable litter or opportunities for stimulation, normal pecking can escalate into undesired behaviors such as feather pecking or cannibalism. Preventing feather pecking is a central goal of species-appropriate husbandry because it leads to injuries and stress. Avoidance is achieved through appropriate design of the environment and management measures.

Outdoor access (free-range access): Outdoor access means that animals have temporary or permanent access to the outside. EU directives and national laws formulate requirements for equipment, hygiene and supervision to prevent, for example, that outdoor access leads to increased disease risk or poor hygiene. Crucial is that outdoor access is not automatically equivalent to good husbandry; design, control and protection from hazards are important.

Stocking density: This term describes how many animals are kept on a given area. For poultry it is often the number of animals per square meter or the body weight per square meter that is considered; for sheep and goats the pasture capacity is decisive. Higher stocking densities increase the risk of injuries, behavioral disorders, husbandry stress and illnesses and require more intensive management. Legal requirements prescribe minimum standards and require inspections so that density and housing do not lead to animal suffering.

Housing systems for laying hens: In short, systems are distinguished that offer hens different amounts of freedom of movement and equipment. At EU level, directives regulate minimum requirements for cages (so-called enriched cages), floor systems and free-range systems; these include requirements for equipment such as nesting places, perches and litter so that hens can perform species-typical behaviors (cf. Directive 1999/74/EC). These requirements are intended to ensure that animals can meet fundamental needs.

Broilers (meat chickens): A common problem with broilers is breeding for very rapid growth, which can lead to muscle and leg problems. Therefore, practice and research discuss adjustments such as the use of slower-growing strains, better barn design, strict monitoring of air quality and regulated stocking densities. The EU also has specific rules on this that contain minimum requirements for housing and monitoring procedures (cf. Directive 2007/43/EC).

Sheep and goats — social needs and management: Sheep are herd animals; close social bonds and group structure are important. Goats are particularly curious and need climbing opportunities and varied feed offers. Both species benefit from pasture access, suitable shelters and management that actively prevents health risks such as hoof problems or parasite infestations. The general obligation to provide farmed animals with adequate housing, feed and care is laid down in EU law as well as national legislation (cf. Directive 98/58/EC and the German Animal Welfare Act).

Part 3 (10 minutes): Applications, Limits and Small Thought Exercises

Objective:

To conclude we apply what has been learned to concrete examples, mention limits of knowledge and give short thought exercises that deepen understanding.

Application 1 — Laying hens in practice: If a farm keeps hens in a floor system, it must provide nesting places, perches and litter so that the animals can nest, perch and scratch. Only when these elements are present and accessible is the risk of behavioral disorders reduced. These requirements are enshrined in EU law; practical success also depends on management, such as feed availability, lighting control and hygiene.

Application 2 — Broilers and stocking density: A farm that keeps very many animals on little space can have problems with air hygiene, high humidity and increased disease pressure. Remedies include lower stocking densities, better ventilation, regular health checks and, where appropriate, the use of slower-growing breeding lines. At EU level there are rules that prescribe how stocking densities and housing conditions must be monitored (cf. Directive 2007/43/EC).

Application 3 — Sheep/goats on pasture: For grazing, the area capacity must match the herd, and shelter options must be available. Sheep show increased stress behavior when shelter is missing or density is too high; goats need structures for climbing. Farm managers must therefore consider pasture management, rotation and protection planning. The legal framework requires adequate care and housing (cf. Directive 98/58/EC and the German Animal Welfare Act).

Limits and uncertainties: Science and law provide guidelines and minimum requirements, but there remain research gaps, for example in precisely determining optimal stocking densities under different climatic conditions or in the question of how genetic breeding goals (e.g. for faster growth) can best be reconciled with animal welfare. Such open questions require further investigations and practical trials. I point out that this lecture only presented generally accepted rules and recommendations; detailed numerical specifications on area or weight are not generalized here and should be consulted in the specific legal and technical texts.

Small thought exercises (short):

1) Consider how the behavior of 100 laying hens would change if they were kept not in a system with nesting places and perches but suddenly only in bare cages without litter. Which behaviors would they miss, and what problems could arise? Justify your answer using the concept of species-typical needs.

2) You plan an experiment to investigate the effect of outdoor access on pecking in hens. Which two housing variants would you compare, which measurements (e.g. feather loss, observation time for pecking) would you record and which control factors must you consider?

3) A sheep flock suffers from parasite infestation after a long grazing period. Which management measures could help, and why would merely increasing the grazing density not be a good solution?

These tasks are intended to encourage transferring what has been learned to concrete situations. It is important to recognize that management, barn design and legal requirements must work together to ensure animal welfare.