engineering

Furnished cage

Furnished cage is a engineering topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Furnished cage rather than just read about it. In short: A furnished cage, sometimes called enriched cage, colony cage or modified cage, is a type of cage used in poultry farming for egg laying hens. Furnished cages have been designed to overcome some of the welfare concerns of battery cages (also called "conventional" or "traditional" cages) whilst retaining their economic and husbandry advantages, and also provide some of the welfare advantages over non-cage systems.

Key takeaways

Furnished cage belongs to engineering; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Furnished cage to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Furnished cage from memory before moving on to harder problems.

Reference excerpt

A furnished cage, sometimes called enriched cage, colony cage or modified cage, is a type of cage used in poultry farming for egg laying hens. Furnished cages have been designed to overcome some of the welfare concerns of battery cages (also called "conventional" or "traditional" cages) whilst retaining their economic and husbandry advantages, and also provide some of the welfare advantages over non-cage systems. Many design features of furnished cages have been incorporated because research in animal welfare science has shown them to be of benefit to the hens.

History and legislation

Battery cages have already banned in several countries including all European Union member states (since 2012 under European Union Council Directive 1999/74/EC), Norway (since 2012) and Switzerland (since 1992). New Zealand will phase out battery cages by 2022 and Canada by 2036. Prototype commercial furnished cage systems were being developed in the 1980s. As alternatives to battery cages, the EU Council Directive allowed non-cage systems and furnished cages. Furnished cages therefore represent a feasible alternative to battery cages in the EU after 2012. For laying hens, Austria banned battery cages in 2009 and furnished cages in 2020. Luxembourg has also banned the use of furnished cages. Germany introduced a "family cage", which has more space than the furnished cages used in other countries; however, consumers in Germany had reportedly been rejecting these eggs by 2011. Caged farming was eventually banned in Germany in 2015, with a transition period to 2025. Outside the EU, Switzerland has already banned both the battery and furnished cage systems. For meat rabbits, Austria has banned the use of cages; Belgium officially prohibits battery cages since 1 January 2020 and will also prohibit enriched cages from 31 January 2024. However, the alternative system of "park cages", in which groups of at least 20 animals are given 800 cm2 (120 sq in) per animal (12.5 rabbits per m2) has also faced heavy criticism from animal welfarists, especially when in early 2020 the Flemish Centre for Agro and Fishery Marketing (VLAM) launched a campaign to consume more rabbit meat. All major UK supermarkets have promised to stop selling eggs from furnished cages by 2025. In April 2010, the Norwegian grocery chain Rema 1000 decided to stop selling eggs from both battery and furnished cage hens by the year 2012. Several more industry groups have decided to voluntarily phase out furnished cages as well, such as NorgesGruppen by 2019 and Nortura by 2024, while in April 2017 the Green Party proposed to ban furnished cages throughout the country by 2025.

EU specifications

Under Directive 1999/74/EC, furnished cages must provide at least the following:

1. laying hens must have: (a) at least 750 cm2 [120 sq in] of cage area per hen, 600 cm2 [90 sq in] of which shall be usable; the height of the cage other than that above the usable area shall be at least 20 cm [8"] at every point and no cage shall have a total area that is less than 2000 cm2 [400 sq in]; (b) a nest; (c) litter such that pecking and scratching are possible; (d) appropriate perches allowing at least 15 cm [6"] per hen; 2. a feed trough which may be used without restriction must be provided. Its length must be at least 12 cm [5"] multiplied by the number of hens in the cage; 3. each cage must have a drinking system appropriate to the size of the group; where nipple drinkers are provided, at least two nipple drinkers or two cups must be within the reach of each hen; 4. to facilitate inspection, installation and depopulation of hens there must be a minimum aisle width of 90 cm [36"] between tiers of cages and a space of at least 35 cm [14"] must be allowed between the floor of the building and the bottom tier of cages;

5. cages must be fitted with suitable claw-shortening devices. Additionally,

(a) if systems of rearing are used where the laying hens can move freely between different levels, (i) there shall be no more than four levels; (ii) the headroom between the levels must be at least 45 cm [18"]; (iii) the drinking and feeding facilities must be distributed in such a way as to provide equal access for all hens; (iv) the levels must be so arranged as to prevent droppings falling on the levels below. As the minimum total area of 2,000 cm2 (310 sq in) per cage allows 2.7 times the minimum of 750 cm2 (116 sq in) cage area per hen, this means that a maximum of two laying hens is acceptable in the smallest of cages.

Furnished cages and battery cages Furnished cages retain several advantages of battery cages in that they

Separate the eggs from the hens' feces thereby keeping the eggs clean Protect the hens from predation Automatically collect the eggs thereby preventing egg-eating and floor-laying which both incur additional cost Retain a small group size which reduces injurious pecking behaviour

Current designs There is no clear limit to the size of the furnished cages. Although initial models were not much larger than conventional battery cages, most current designs house 40 to 80 hens although one system houses 115 hens. The depth of furnished cages is often more than the depth of battery cages and as a result, they are often arranged with only one cage row per level, i.e. not connected back-to-back. The more shallow cages can be connected back-to-back. To create space for large groups of hens, some designs of furnished cages are very long. Cage bottoms are made of wire mesh or plastic slats and are sloped so that eggs not laid in the nest box roll onto an egg belt. Feed is provided in feeders outside the cage, although in some designs there may be internal feeders or a combination of the two. Perches in some designs are raised and in others are at floor level.

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with Furnished cage

Start with the simplest possible case. Write down what Furnished cage claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In engineering, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Furnished cage before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Furnished cage ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Furnished cage

In research: Furnished cage appears in engineering research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Furnished cage in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Furnished cage is common in secondary-school and first-year university syllabi. It links to neighbouring topics Animal welfare, Buildings and structures used to confine animals, Poultry farming, so understanding it makes those chapters shorter.
In everyday life: Look for Furnished cage outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Furnished cage in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Furnished cage means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Furnished cage out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Furnished cage in simple terms?

Why does Furnished cage matter?

Because it connects several engineering ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Furnished cage?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Furnished cage.