Floor vs battery cages: Which is the best system?

Poultry farmer Peter Kimani feeds his hens at Wakio farm. [David Njaaga, Standard]

Egg production farming is a lucrative business in Kenya. The industry has a population of 5.58 million commercial laying flocks producing about 1.6 billion eggs annually, according to the 2019 census results.

Many of these egg producers’ aim is to get the best products from their investments.

They do this by many years of experimenting with their own management system that involves different types of housing, depending on the climate, available land, and ever-changing market conditions.

The poultry industry has steadily been growing at 7 per cent per annum providing a livelihood to many farmers.

As the demand for cheap protein increases, so is the quest to rear more birds in limited space and thus the popularity of battery cages.

Although 90 per cent of our layer flocks are reared in deep litter or floor systems, more farmers are now adopting battery cage systems in egg production because of the perceived benefits.

Battery cages vs deep litter?

Battery cages are a housing system used for egg-laying hens. The name arises from the arrangement of rows and columns of identical cages connected as units of four to eight tiers as in artillery battery.

On the other hand, the deep litter system is the traditional rearing of birds on the floor where they have more freedom to move around, scratch, stretch, flap, and ruffle.

Criticism on system

In the recent past, there has been a lot of criticism against the battery cage system,s especially in developed countries.

The system was popular until 10 years ago when animal welfare crusaders raised concern about the extreme restriction of animal range.

Today, more developed countries are legislating against battery cages and as result, more idle cages are finding their way into African poultry farms where the perception of animal welfare is still in its infancy stages.

So what are the pros and cons of the cage against the floor system?

Pros and cons of Battery cage system

1. Initial Housing costs

The initial cost of establishing poultry units in a cage system is higher than an in-floor system.

In the Kenyan context, for the first 16 weeks, the pullets are reared in-floor system before they are transferred into cages.

This in essence establishes a rearing and a production unit.

For 1,000 layers, a farmer will roughly spend Sh250,000 (250 per pullet) on iron sheets, wire netting, ballast and sand, cement, timber, and labour to construct a poultry unit.

The cost of battery cages is approximately Sh300 per pullet.

These expenses will be spread over the period of production and must be paid from the proceeds of selling the eggs.

I have not included the cost of rearing the birds to point of lay, which is about Sh280 per bird.

This makes the pullet more expensive until the amortisation cost is fully paid for or realised in the first cycle.

A farmer will have to do several cycles before realising a net profit.

2. Space allowance- making maximum use of space

The living space is one of the highly discussed topics in battery cage systems today.

Is it reasonable to give birds as little as 450 centimetres square with no opportunity for escape?

It is worth noting that chickens were the first animals to be domesticated over 5,000 years ago and over that period, their movements have been steadily restricted.

For the cages, the biggest advantage lies in the ability to rear a large number of birds per unit.

The most widely used system is the four-deck reverse cage, where each cage can hold three or four birds, making maximum use of space.

More chickens can then be kept in a cage system compared to the floor type.

Ethologists (scientists who study animal behaviour) however disagree saying the chickens are denied the ability to stretch, freely turn without touching each other, flap their wings, scratch the floor, and nest.

To some enlightened consumers, this whole philosophy of intensive farming where bird’s freedom is restricted makes them question the morality of consuming eggs and meat from these caged chickens.

Does stressed bird equal bad meat?

In countries where animal welfare is taken seriously, governments have passed legislation to ban battery cages altogether because the cages do not allow access to nest, perch, litter to allow pecking and scratching, and unrestricted access to feed.

In Kenya, there is no law that stops farmers from cage farming to date. However, as global trends show, it will happen, it’s a matter of time. But for now, it is legal.

3. happy chicken more eggs?

There are people who hold a strong belief that chickens would not grow optimally or produce more eggs if they were ‘unhappy’.

But how do you define happiness in chickens?

There are so many factors that determine the level of production that make it an unreliable tool to measure the wellbeing of birds.

Egg weight on the other hand is 40 per cent heritable that is genetically selected. It is also determined by body weight at the point of lay, nutrition level, and the lighting programme.

Neither of the two systems has any edge over the other on egg weights.

4. Physical health

A healthy bird or flock is described as one that has no overt disease, low mortality, has bright eyes, has good plumage, is alert and active.

A sick bird will show inappetence, coughs, scours, lame, huddles, etc. These observations are however subjective and will vary from one bird to another.

It is however agreed that chickens in cages tend to have higher longevity, have less manure-borne infections, suffer less cannibalism, worm infestation, feather, and vent pecking, and are less aggressive.

It is easier to pick out sick birds in a cage for treatment.

The main downside, however, is that birds in cages do not exercise enough and therefore suffer from fractures of long bones and the keel bones towards the end of production, a condition referred to as osteoporosis.

5. Mortality rates

Physical restrictions cause a differential rate of freedom from social conflicts in favour of birds in cages.

Farmers have encountered lower mortality in cages compared to cage-free floor systems by a difference of one to two per cent.

Birds on the floor system require more keen and frequent observation and the ability to pick sick birds very fast before they are bullied by the stronger and healthy mates.

There seems to be more aggression, cannibalism, and a harmful pecking-in-floor system.

If you are keeping 10,000 layers, a one per cent mortality is quite significant, that is equivalent to 35,000 eggs lost over the entire laying period, without including the cost of rearing the pullet.

6. Labour and husbandry practices

Since cage farming is highly intensive, 10,000 birds can be easily managed by one individual as feeding, water supply are all automated.

The poultry worker’s job is to collect eggs and remove any dead bird from the cage.

It requires less animal health and production knowledge.

In a deep litter floor system, biosecurity can easily be breached especially during visitation by contaminated dirty feet and clothes.

The biggest nuisance in the cage systems is the removal of raw manure, if the process is not done through a conveyor belt system, it can lead to poor air quality and flies menace if the litter is not removed on time.

7. Egg quality

The battery cage floor is designed in a sloppy way that allows eggs to roll to the front of the cage as soon as it is laid.

The eggs are therefore cleaner and have a longer shelf-life than in a deep litter system, where floor eggs tend to go bad within few days of storage.

Ethologists however insist that birds prefer to lay eggs in nests away from the eyes of cage mates and that denying the birds their natural behaviour to seek nesting areas is interfering with their comfort and preference.

8. Feed waste

It is certainly true that the distribution of feed in the cage system is faster and with little spillage compared to the deep litter system.

In the latter, birds will scramble during feeding and spill a lot of feed.  

There is more competition for feed and water space in-floor system, creating less stable social groups.

This could lead to behavioural problems like feather pecking and piling.  

Feed accounts for 70 per cent of the total cost of production and therefore any loss will translate to few eggs per kilogram of feed allocated.

At peak production with robust feed quality, a good farmer will achieve a feed conversion ratio of seven eggs per kg of layers mash.

This can easily drop to five eggs/kg of feed in a system where feeding is manually done on feeder tubes, slow feed distribution, and uneven feed intake and waste of feed in the litter.

9. Air quality

Chicken manure is rich in nitrogen, phosphorus, potassium, and other nutrients and therefore is potentially a major source of pollution of air, soil, and water.

In a layer production system, the effects of ammonia and dusty environment are rarely mentioned yet the two can affect the production in both systems.

In a battery cage system, the single biggest problem is the removal of raw chicken droppings.

It is laborious and in situations that there is a delay in removal, ammonia gas generated can cause damage to the eyes and respiratory linings.

In the deep litter system, the combination of ammonia and dust can irritate the respiratory system, so predisposing birds to pneumonia.

It is common to see farmers remove old litter from the units for sale during the planting period and in the process cause a lot of dust in the environment.

In the cage system, the installation of a conveyor belt below the cages will help in the removal of the litter with little disturbance to the birds.

10.  Fly menace

Fly infestation is a major challenge in all poultry operations.

Poultry manure is an ideal medium for fly reproduction.

In cage systems, the fly menace is a big issue especially in our case where farmers are not installing automated manure conveyor belts.

Flies cause discomfort to birds, stress leading to decreased egg production.

Flies also serve as vectors to most of the microorganisms that cause diseases like Botulism, coccidiosis, E. coli infections, Newcastle, salmonellosis, and Avian influenza.

There is no inherent advantage of one over the other, it's all about good husbandry practices.

11.   Quality assurance schemes

In more developed poultry production countries, there are schemes or partnerships between producers and retailers that ensure that consumers of products (either eggs or meat) get the best quality assured product.

These schemes have developed essential quality assurance requirements for eggs or meat throughout the production cycle up to the final delivery to the customer.

Independent audits are done to ensure that the producers are true to their commitment to the welfare of the animals, especially on the five freedoms.

The five key freedoms 

These freedoms include freedom from hunger, malnutrition, and thirst, freedom from fear and distress, freedom from physical and thermal discomfort, freedom from pain, injury, and disease, and freedom to express normal patterns of behaviour. 

The producer who successfully abides by these conditions is then certified and gets a mark of quality on the label of their products.

Consumers are slowly forcing producers to conform to animal welfare standards, and that is why the battery cage system is slowly getting phased out even with all its inherent advantages.

The jury is still out there on how long Kenyan farmers will continue using battery cages over our traditional floor system.

For now, the backstops are at the consumer preference.

[The writer is the Head Vet at Kenchic]