Multi-tier laying hen techniques are rising in reputation, permitting extra birds to be saved in a given shed footprint. Nevertheless, it is very important perceive the extra welfare concerns of utilizing these setups.
Vicky Sandilands, senior behaviour and welfare scientist at Scotland’s Rural School, carried out a analysis venture evaluating multi-tier and flat-deck techniques and that additionally appeared on the worth enrichments may supply.
These are her fundamental findings, which will likely be unveiled in full on the British Pig & Poultry Truthful on 10-11 Could.
See additionally: Professional tricks to cut back poultry vet and drugs prices
What are the principle variations?
Multi-tier techniques are costly to put in. Nevertheless, one of many advantages to producers is that they’ll put extra birds in a multi-tier system in comparison with a flat-deck, however with the identical shed footprint.
“Some farmers had been adamant they weren’t going to make use of multi-tier because it was unhealthy for the birds, however others had been saying it’s good for them as they transfer via the house as they might do naturally in the event that they had been going up timber to roost,” says Dr Sandilands.
Dr Sandilands’ analysis didn’t present a big distinction between the 2 techniques when it comes to mortality, though it was barely larger within the flat-deck system (7.5% in flat deck, in contrast with 4.8% in multi-tier at 70 weeks of age) throughout 42 flocks, visited between 69 and 90 weeks of age.
“A better mortality fee and decrease common egg manufacturing, attributable to much less birds within the flat-deck system, makes a big distinction financially in favour of the multi-tier system.”
She discovered a £10.32 margin a chicken over feed to 70 weeks in a flat-deck system versus £10.92 in a multi-tier one.
Nevertheless, keelbone injury was a lot larger within the multi-tier system; keelbone deviation was discovered to be 48% in comparison with 28%.
“We all know it’s extra prone to happen the place birds have the power to maneuver round quite a bit – like in multi-tier techniques, the place birds need to descend to a crowded ground,” says Dr Sandilands.
Common share of flocks with keelbone fractures and deviations |
||
Keelbone fractures |
Variety of birds in pattern group |
|
Flat deck |
28% |
690 |
Multi-tier |
48% |
460 |
Keelbone deviations |
Variety of birds in pattern group |
|
Flat-deck |
3.2% |
690 |
Multi-tier |
7.4% |
460 |
When descending, they’re making an attempt to land on a busy ground with different birds and furnishings – which could be a supply of damage because the keelbone dips or twists.
The share of flocks with keelbone fracture is nearly double in a multi-tier system (7.4%) in contrast with a flat-deck (3.2%).
It is a actual welfare concern, says Dr Sandilands. “The issue is, you’ll be able to’t see it.”
So how do you cut back it? “One of many suggestions is to offer ramps, so birds can stroll down between tiers – they’ll additionally assist to interrupt birds’ fall if they’re knocked off.”
How enrichments may help
Dr Sandilands has additionally checked out whether or not varied technique of enriching the birds’ setting are efficient. “Enrichment is a crucial consideration in relation to chicken welfare, with advantages comparable to lowering feather pecking.
“Some accreditation schemes additionally require one enrichment for each 1,000 birds. We had been curious concerning the enrichments that free-range and natural producers had been having to place in, had been they actually any good?”
She checked out 4 totally different enrichments, offered at a fee of 1 enrichment to 1,000 hens. In each 4,000-hen colony there have been not less than 4 enrichments of two differing kinds, to adjust to rules.
The enrichments had been: lucerne hay bales, pecking blocks, scattered feed and twine. “Rope is a generally used enrichment as a result of it’s low cost. We wished to primarily use enrichments that had been already getting used on farm as a result of we felt it was extra essential to guage these than attempt one thing new.”
Key welfare findings
- Scratch mat design doesn’t make a distinction to hen behaviour
- Ropes don’t generate a lot curiosity however they’re the most cost effective so could also be value providing alongside one other enrichment
- Multi-tier techniques have the best threat of keelbone fracture and deviation in contrast with flat-deck techniques
The birds had been noticed inside a 1m radius of the enrichment – this was classed as displaying curiosity, whereas these additional away weren’t.
The research confirmed that scattering feed did create loads of curiosity. “The feed was scattered twice a day at a fee of 1g a chicken. We noticed a peak of curiosity within the space the place the feed was scattered in addition to steady curiosity within the space after the feed was depleted.
“Some rules don’t class scattering feed as an enrichment as a result of it isn’t repeatedly obtainable – so we did need to get permission for the farms to make use of it within the research,” she provides.
Whereas there was constant curiosity in peck blocks and bales, there was least curiosity in ropes. They’re generally used as a result of they’re low cost however they could as effectively not be there; there was no distinction when evaluating the 1m circle across the ropes with the world outdoors of the circle.
“That could possibly be as a result of the birds don’t discover the ropes attention-grabbing or as a result of they’re simply 30cm lengths looped over a rail – they aren’t very massive in comparison with a bale or pecking block,” she says.
Dr Sandilands additionally calculated the price of offering enrichments for a flock of 16,000 hens housed for 80 weeks. Together with alternative of the enrichments when obligatory, the bales value £2,000, peck blocks £6,500 and pelleted feed £3,000, however ropes had been £6.54.
So, financially, ropes are a beautiful possibility. “If you need to present two several types of enrichment for each 1,000 hens, the ropes are low cost, so could possibly be paired with one other enrichment. Chances are you’ll not wish to spend near £9,000 when you’ll be able to spend £2,000.
“That’s one of many realities – you need to steadiness it with what’s sensible. In case your accreditation stipulates two enrichments, maybe think about providing ropes as one and peck blocks or bales as a second.”
Are scratch mats worthwhile?
Welfare laws requires producers to offer litter, permitting pecking and scratching in enriched layer cages. Because of this, cage producers supply quite a lot of totally different scratch mats of assorted sizes, shapes and supplies.
The concept behind the scratch mats is to encourage pecking and scratching behaviour, as within the wild chickens would spend loads of time foraging for meals.
“I wished to seek out out if it truly made a distinction to the hens when it comes to the time they spent there and proportion of time they spent displaying foraging-type behaviours,” says Dr Sandilands.
In a industrial setting, producers dispense a small quantity of feed onto the mats to encourage foraging, however because the mats aren’t very massive, solely two or three hens will match on them at one time.
“The feed is rapidly depleted, preliminary curiosity is misplaced and so they could look to peck at one thing else – like one another, resulting in feather pecking.”
Regardless of the totally different sizes and designs of scratch mats, there didn’t seem like an optimum one and total use was low.
Nevertheless, Dr Sandilands acknowledged that industrial hens aren’t used to folks standing and observing them, which can have affected their behaviour and trial outcomes. “For scratch mats to be efficient I feel feed must be distributed onto them continuously.”
Predicted bodily efficiency and monetary margins over feed |
||
|
Flat-deck |
Multi-tier |
Egg yield per chicken to 70 weeks (hen housed) |
283 |
286 |
Cumulative mortality to 70 weeks (%) |
5.6 |
4.8 |
Common second-quality eggs to 70 weeks (%) |
3.8 |
3.4 |
Common feed consumption (g/chicken/day) |
123.7 |
120 |
Margin per chicken over feed to 70 weeks (£) |
10.32 |
10.92 |