Future flock
Some free-range chooks lay substantially more eggs than
others, and Manisha Kolakshyapati, from The University of
New England, is trying to find out why.28 – COSMOS Issue 86
BROUGHT TO YOU BY THE
AUSTRALIAN COUNCIL OF DEANS
OF AGRICULTURE
demand for free-range eggs has led to
a substantial increase in production in
Australia and elsewhere over the past
decade. In 2010 just 25% of Australia’s
eggs were free-range, now it’s around 40%
of the 100 million eggs sold each week. Of
our 19 million egg-laying chickens, about
10 million are housed in cages, with the rest
in barn or free-range production.
Free-range flocks often perform poorly
compared with hens housed in barns
or cages and within free-range chook
populations, some chickens are better
layers than others. Kolakshyapati set out
to find out why and quickly discovered that
the reasons are surprising.
“Chickens always form
subpopulations,” she says. “In free-range
populations, some hens will always go
outside if given the opportunity. We call
these ones the rangers. Others prefer to
stay inside the sheds.
We call these the stayers.”
Different farms have different
percentages of stayers and rangers.
For example, in the UK (perhaps where
conditions are colder outside) up to 50% of
a free-range population may be stayers, butin Australia the average percentage is 10%.
Kolakshyapati initially thought that the
rangers would be using more energy to
move around further, so would probably
not be as productive in terms of laying
eggs as they would be using the energy for
mobility. “But the ones that were going
outside were producing more eggs,” she
says. “We were expecting the positive
production difference in the stayers, but it’s
happening the opposite way.”
The surprising result has led
Kolakshyapati and other researchers
on a quest to try to determine why –
considering factors such as genetic
differences or dietary differences (rangers
may be ingesting more dirt, or pasture or
microbes that could be helpful).
One of the key differences she has
found is that the stayers seem to be more
fearful birds, and this is likely to be affecting
their production. When she took a group
of stayers and a group of rangers into a
different environment, the stayers showed
more fearful behaviours – for example,
in their interaction with a new
environment.
“If a hen is stressed, she will allocateFROM THE
FRONT LINE
Manisha Kolakshyapati, animal researcher
at The University of New EnglandMANISHA KOLAKSHYAPATISPECIAL FEATURE
Growing up in Nepal, Manisha
Kolakshyapati was surrounded by
animals. Her father was a professor in
agriculture and the family lived on a
university campus. “We had access to a
whole lot of animals and I enjoyed being
around them – I liked it there,” she says.
It therefore wasn’t a huge surprise
when Kolakshyapati decided to follow her
father’s footsteps, working with animals
and exploring how to improve food
production. Initially studying veterinarian
science in Nepal, she went on to pick up
two postgraduate degrees – a Masters
in Animal Science, from the Swedish
University of Agricultural Sciences,
and a Masters of Food Science from the
University of Helsinki.
She returned to Nepal to work as a
scientific researcher and veterinarian for
the government, and now she’s working on
a PhD at the University of New England.
The focus of much of Kolakshyapati’s
early research was on broilers, but for the
past two years she has been targeting egg
production, and in particular production in
free-range chickens.
The rise of consumer interest in and