WATT PoultryUSA - April 2018 - 20
20 ❙ WATTPoultryUSA
SLOWER BROILER GROWTH, NATURAL LIGHTING
ultimately, feed conversion ratios was discussed by the
panelists, too. GAP standards call for inclusion of natural
light in the broiler house in its Step 2.
Shepard, speaking about Wayne Farms' adoption of GAP
standards, said increased light levels do increase activity
but it comes with a significant drop in feed conversion ratio.
Moving from 0.5 foot candles (FC) of light to 2 FC costs
three points of feed conversion. Increasing it further, to 5 FC
from 2 FC, is another four points of feed conversion.
This is significant, Shepard said, because four points of
feed conversion lost translates to about a million bushels
of corn per year. That's extra feed that needs to be grown,
purchased, and transported by train from the Midwest
to the South, which raises questions about sustainability.
More scientific research is needed to define what lighting
is best for both welfare and operational sustainability.
"We cannot go overboard too much so that we waste
the sustainability," Shepard said. "Whatever we do, I'm all
for animal welfare and we'll balance it, but just to swing
the pendulum, so to speak, farther than what we need to
has implications for sustainability and that concerns me."
Wayne also noticed more scratching and cuts on the bird
when it first increased the intensity of its lighting, but it was
able to counteract it by changing its feed formulation to increase the protein level which improved feather coverage.
The role of natural light
As for the inclusion of natural light in the poultry
house, Mench said she's unsure if there's ever been a direct comparison, but with light emitting diodes (LED), it
should be possible to simulate the full spectrum of light
provided by the sun. This is important since birds can see
ultraviolet markings that humans can't.
It should be possible to duplicate natural light in the
poultry house using LED lights. Producers and researchers also must consider what welfare impact comes from