Issue 86 COSMOS – 29energy towards a physiological stress
response and, if this is a chronic state of
stress, it will have long-term impacts on
welfare and productivity,” she says.
“Evaluating the egg albumen
corticosterone level, an indicator of
physiological stress, we showed that
stayers were less resilient to stress and
took more time to recover after a stressful
event. Stayers likely allocate more of
their energy to a physiological stress
response, leaving less energy for
production, growth and maintenance.”While the corticosterone results
indicated that the stayers were less
resilient to stress compared to the rangers
and a control group, these results aren’t
definitive on their own and are being
compared with behavioural studies to
develop a better picture in regards to the
link between fear and poor egg production.
The differences between the rangers
and the stayers might resolve over time.
“With time, most of the stayers started
going out more,” Kolakshyapati says. “We
see that the heavier pullets end up beingrangers, and the lighter ones are stayers. So
it might be related to weight.”
There’s no doubt Kolakshyapati still
has great enthusiasm for her subject, even
as her PhD moves into its third year. This is
particularly helpful as she looks at the role
of gut microbiota and the role it could have
on egg laying. “Studies into environmental
enrichment could also show an effect,” she
says. “The free rangers seem to like a new
environment, so maybe that could be a
factor. The more we look into it, the more
we find to look into.”SPECIAL FEATUREFABA-PHOTOGRAHPY / GETTY IMAGES