multi-tier poultry© Tim Scrivener

Free-range egg production has seen plenty of advance and innovation over the past 20 years.

From the early 4,000-6,000 bird “on-floor” straw litter units, to the introduction of flat decks with roll-away and then auto-nest boxes, right up to the advent of 32,000-bird, “back-to-back” units, it has been a story of steady progress.

But, in terms of bird welfare, as well as profitability for the producer, the arrival of the multi-tier laying system in 2006 is the most significant advance of all.

See also: Multi-tier units put laying hens on a firm footing

It is actually quite surprising that a system that so clearly meets the welfare needs of the bird, as well as delivering economic and management advantages to the producer, took so long to be brought over from the Netherlands.

Design tip

Add bird ladders/ramps to either side of the system to encourage birds to access all the tiers.

Since 2006, a number of further improvements have been made to the design of multi-tier units and they are even more user friendly than they were at the outset.  

Of course, to get best results, producers need to understand the strengths and weaknesses of the system they are working with. It is crucial to pay close attention to detail and, where you can, incorporate design elements that will improve bird welfare, and help you run the system more efficiently. 

Overall benefits

Multi-tier systems encourage the hens to move freely up and down, allowing for a natural pecking order and for subordinate birds to get away from aggressors. Birds are more active generally and overall this results in healthier, contented and less stressed birds – and more productive flocks.  

Introducing a new flock

It might be cheaper to buy in pullets that haven’t been reared in a multi-tier system – but not in the long run.  If you do buy pullets reared in a different system, you are likely to be spending a great deal of time physically lifting them on to the system and, at a later stage, even more time picking up floor eggs.

Bob Waller with multi-tier poultry

Bob Waller ©Tim Scrivener

Buying pullets reared in a multi-tier system is also a requirement of Freedom Food, if they are going on to a multi-tier system. 

Perching is another issue to look out for. Often pullets going into a laying shed are not used to perches because some rearers will not have enough perches for all of the birds in the house at various heights. As a result, some birds won’t go up or down to feed and drink.

Also check that your rearer is using ramps/ladders in the pullet rearing system. Again, if the birds are used to using them, they will adapt much more quickly to your multi-tier system. So, go and look at the rearing system you are buying from to make sure it is compatible. 

Also, when planning your next flock, consider the best breed for a multi-tier system. A more active breed than you might choose for a traditional system would be best.

Flock inspections

Daily checks are less stressful – for the birds and the producer – mainly because it is easier for them to get away. You do need to keep moving around on inspections, as birds will crowd around if you are too static, with the risk of smothering.

Design tip

Fit personnel ladders to either side of the unit to allow easy viewing across the system. Fit grab handles to allow a longer and safer reach.

Litter and air quality

In general, higher levels of air and litter quality are maintained in multi-tier systems. If you are moving from a flat deck/traditional system you will notice there is less ammonia – particularly when the flock gets towards end of lay, when manure build up in conventional systems is at its greatest.

That said, attention still needs to be paid to litter management. With pop holes down both sides, the increased air flow helps to keep the litter friable, but any areas of wet or compacted litter will not vanish on their own overnight.

Deal with it as soon as possible and, if an attempt to loosen it and make it more friable doesn’t work, get rid of the wet stuff and start afresh.

Heat retention

This is another advantage of multi-tier, as birds can move away from draughts from pop holes to the upper tiers where it stays warmer. 

Design tip

If possible, put in more pop holes than are required. You can then close some of them against prevailing winds to keep the building at the right temperature, without contravening any assurance requirements. This could also result in reduced feed consumption, due to warmer shed temperatures.

Introduction to the range

Birds must go out by 21 weeks, but letting them out sooner if it is practically possible, will help to reduce litter compaction and maintain quality.

Also, if you have fitted electric wire to prevent birds gathering in corners, then ensure that it goes over the top of the pop holes so birds can access the range without danger of being shocked. 

Mortality and culling

This is one particular area where multi-tier does not deliver an advantage. Inevitably, it can be more difficult to spot the birds – although weaker birds are more likely to be found at floor level. 

Design tip

Make sure your pop holes are the correct size for your assurance scheme – especially if you have added an internal wooden frame.

Any dead birds should be removed every day – ideally on your first walk round. And any birds in need of culling should be placed in a bag to contain wing flapping. If the birds to be culled are removed to a holding area before dispatching, make sure they have a little feed and water available. 

If you use egg collectors, they should look for dead or weak birds and report back immediately, so that prompt action can be taken.

Design tip

Personnel ladders will be a great help here.

Depopulation

This is another challenge. You need plenty of staff as birds are not so easy to access as in conventional systems. It needs to be done with care and not rushed. Remember that birds at end of lay will not have the weight and feathers to protect them – they need to be passed carefully off the system and on to the module.

Try and use a one-way system so that there isn’t a bottleneck when carrying birds through the door. If you are using catching teams, make sure they are fully briefed and understand the particular needs and pressures of depopulation in multi-tier.

Design tip

If you are designing from scratch, don’t overlook the optimum way to get birds in and out of the house. Consider adding personnel doors half way down the side of the building, so that you can use a one-way system for stocking and depopulation. It might take a little longer, but will be less stressful for the birds, and they will settle more quickly.

Record keeping

Good record keeping is the backbone of running a good system – and is as much about maintaining high standards of bird welfare as it is safeguarding profitability.

Keeping good records means you can monitor trends. What was the reason for culling the birds? Normally, it is because the birds were a poor weight when they first came in.

This is another good reason to visit your pullet rearer before taking a new consignment.

Always record floor eggs – then you can see overall how many you have had to downgrade to seconds. It will focus the mind. Record use of water daily – changes here can be an important early warning system.

Scrupulously maintained records should be the absolute first port of call for relief staff – especially if there is not time for a full handover. 


Bob Waller is the former agricultural manager for Freedom Food and now runs Partners in Welfare – a consultancy for producers preparing for audits and maintaining compliance.