Enriching pens impacts the behavior of broiler breeders on restricted-feeding regimes, the results of a University of Georgia study suggest.
Skip-a-day feeding programs are used to manage bird bodyweight but can result in stress and affect their overall welfare.
To test whether environmental enrichments could alleviate this, a team of scientists allocated 2,540 birds to pens using four treatments: a skip-a-day program in pens with perches, string and compact discs; a skip-a-day program without enrichments; and every-day programs with and without enrichments.
They measured blood-plasma corticosterone, which is associated with stress in birds, at days 10 and 22, and monitored behaviors for three 1-hour periods on a feed day and non-feed day.
Results presented at the 2023 International Poultry Scientific Forum showed that birds on the skip-a-day regime in the pens without enrichment had lower levels of corticosterone and demonstrated more spot- and feeder-pecking behavior.
Initially, the finding of lower corticosterone levels in birds from unenriched environments “was very surprising to see,” said Camille Evans, the graduate research assistant who led the study.
“However, previous research in pigs and rats has found that chronically stressed animals, when given access to environmental enrichments, can have higher corticosterone concentrations when compared to animals in barren environments,” she noted.
These findings may also suggest a depression-like state in the birds on reduced feed with no enrichment. However, further work is needed to confirm this.
A route to behavioral improvements?
In comparison to those in unenriched pens, birds in the enriched pens also engaged in fewer pecking behaviors than those fed every day.
A significantly greater percentage of birds in both of the skip-a-day treatments carried out foraging behavior than birds fed every day, while birds on a skip-a-day diet but with enrichment used perches more on no-feed days.
“I believe my research shows that environmental enrichments do have positive effects on broiler breeder behavior, and I hope to see them implemented in the future,” Evans added.
“My enrichment types are relatively cheap and would not require a lot of labor to set up, so I believe that producers would be able to add them to their operations at a low cost and see the benefits.”