Canadian Poultry Magazine

Peck a block, spare a feather

By Ronda Payne   

Features Welfare

There’s a growing body of research assessing the use of pecking blocks for broilers to reduce feather pecking. Now, scientists have started testing them in enriched layer housing.

While usually used in floor barns, scientists have begun to modify pecking blocks for enriched cages. Photo: Probiotech International Inc.

Laying hens naturally forage. Without options to participate in this behaviour, they often resort to flock-harming activities like pecking each other, which can increase injury and mortality in fellow birds. Pecking blocks are proving to be a better solution than the code-required scratch mats.

While European and Canadian farmers have already begun using enrichment devices like pecking blocks in non-cage housing systems to enhance foraging, the research in this area is sorely lacking. That’s where Tina Widowski, a professor in animal biosciences and core faculty member at the Campbell Centre for the Study of Animal Welfare for the University of Guelph, comes in. 

She is involved in a study assessing the ways packing blocks can be best used in enriched housing colonies to improve animal welfare. 


The job of a laying hen
“The code of practice for laying hens requires supporting of foraging behaviour. In enriched colonies, hens are only given scratch mats at this time. Scratch mats can become soiled with feces and they do not provide much variety,” Widowski says. 

“Under natural conditions, hens spend 60 to 70 per cent of the day foraging. This is their ‘job’ – looking for food. When they are provided all of their food in a concentrated form, they have no job, so they redirect foraging behaviour at each other’s feathers, leading to feather pecking and poor feather coverage.”

When the code of practice was being researched, finding ways to optimize enriched housing to better support natural behaviours like foraging was identified as a need. While scratch mats were the first solution implemented, Widowski and others think pecking blocks are a better option. 

Leanne Cooley, poultry scientist and Poultry Animal Auditor Certification Organization auditor with L.H. Gray & Son Limited, sees tools like pecking blocks in enriched environments as a beneficial solution. 

“L.H. Gray & Son Limited Farms have always provided a variety of pecking enrichments in our cage-free barns,” she says. “Historically, these ranged from items like hanging bales of forage (hay), to insoluble grit, to hanging colourful plastic bottes and shiny CDs. 

“In 2017, we began routinely using Vilofoss PECKStones. In 2021, we began evaluating Alltech ChikPek blocks, and in 2023, we were introduced to Probiotech’s Happy Block. Presently, we only offer supplemental pecking enrichments in our cage-free barns.”

The problem of feather pecking
Widowski says a previous study, done before the Code of Practice for Egg-laying Hens was updated to include scratch mats, showed that feather conditions in hens in enriched housing were worse when there was no scratch mat. But, as previously noted, scratch mats aren’t the best option.

No scratch mat or better option to meet the hens’ foraging need means hens will resort to feather pecking. Canadian farmers need to consider solutions like pecking blocks to ensure that natural job is fulfilled and, thereby, reduce feather damage as they make the switch away from battery cages. 

While other variables have been associated with feather damage in large groups of birds, incorporating foraging options into enriched housing can make a difference with minimal flock disruption. 

Mild feather pecking is natural in colonies for the establishment of pecking order (this is where the cliché originates), but when the behaviour grows beyond normal hierarchy establishment, it can turn severe to a state of cannibalism. This harmful behaviour can be learned and spread through the flock quickly because of hens’ tendency to imitate each other. 

Once it starts, severe hen pecking (yes, another cliché) is extremely hard to stop and results in reduced egg production, reduced hen welfare overall and increased mortality. 

Results to date and non-scientific observations
Although the study is not yet complete, it is promising to see hens mimicking each other’s behaviours in using the stones while also showing greater consumption of pecking stones at night. 

“The birds appear to learn the behaviour over time as pecking behaviour and block disappearance increases the longer the birds have the blocks,” Widowski says. “Pecking at the blocks increases near the end of the day; at least with the mineral (calcium)- based blocks. This might be related to the hens’ physiological needs for calcium for eggshell formation at night.”

The blocks being used in the study are already commercially available and Widowski promises to provide details on implementing blocks into flocks including: frequency, duration, placement, quantity and replacement rates. She asks producers to stay tuned for more details as the study concludes. 

Pecking stones in broilers have been positively received by birds who peck and use it as a perch, but feather pecking is less of an issue in broilers than in laying hens. 

Although not part of the study, Cooley’s observations are positive and support the need for interactive forage above the litter floor. Food reward, colour and motion have all shown positive results. 

“We observe highly visible and colourful enrichments are very well utilized. Any items that are hanging/suspended at bird head height or a little higher are regularly in use,” she says. 

“Edible pecking blocks need to offer enough of a food reward during pecking to continue to be utilized by the birds or they will lose interest. Inedible pecking objects need to be colourful and generate some type of movement or interesting sound when pecked.”

Any edible blocks placed on the litter floor are less used as they blend in to the environment and are covered with dust and feces quickly. These should be suspended or mounted over the floor areas to generate ongoing use. But overall, she has found anything on the ground needs to be large, colourful and raised to ensure continual interest.

“We observe the birds spend as much time pecking at the coloured plastic base as they do the mineral stone itself and we often continue to use the plastic bases in various ways as enrichments in the barn after the stone has been consumed,” she says. 

“Overall, we observe our best results by offering combinations and variety of pecking-foraging enrichments. We observe even greater utilization in the lay barns when we also introduce them during pullet rearing.”

She has seen an improvement in foraging behaviour and a reduction in aggression between birds as a result of pecking stone introduction. This has led to improved maintenance of feather cover, which she sees corelated to improvements in livability and feed efficiency.   

“We also find that placing enrichments in a uniform pattern across the barns assists us with keeping birds evenly distributed across the litter areas and can be used to attract birds to spend time in underutilized spaces,” she says.

While not conclusive, it seems that pecking stones make a strong enrichment option for laying hens. If introduced in ways that avoid excess dust and feces, the blocks can create continuous benefits for hens in enriched housing. 

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