MEAT+POULTRY - June 2015 - 78

FROM THE CORRAL

Avian issues continue

Photo by Rosalie Winard

The results of a major study on the advantages and
disadvantages of different types of laying hen housing
were presented at the Midwest Poultry Conference in
Minneapolis in March. People were eagerly awaiting these
findings because many egg producers are concerned on
how they are going to comply with California's new rules
on space for laying hens. The rules require that a laying
hen can fully stretch her wings.
Dr. Joy Mench, Univ. of California-Davis, was one of
the leaders of the study conducted by the Coalition for
Sustainable Egg Supply. McDonald's Corp. and many other
stakeholders participated in this research.
Mench explained that this
was the first US study to compare
three different types of hen
housing in actual commercial
houses. The systems that were
evaluated were: 1) conventional
battery cages, 2) colony housing,
and 3) aviary cage free. In a colony
system, the hens are still in cages
but they provide amenities that
enhance hen welfare. A hen in
a colony house can stand at full
posture, has a secluded nest box,
perches and a pad to scratch on.
To keep conditions constant, all
three systems were stocked with
Maybe to stop
Lohman white hens.
some of these
There are trade-offs, and
diseases, we
advantages and disadvantages of
each system. The aviary system
need to start
had the highest ammonia, dust
breeding
levels, dirty egg shells and death
animals for
losses. Egg shell cleanliness, death
losses and air quality were similar
optimum
in both conventional cages and
production
colony housing. The aviary system
instead of
was the best on condition of the
hen's bones and prevention of
maximum
loss of feathers. (To see a chart
production.
which compares and contrasts the
three systems, you can visit
www.sustainableeggcoalition.org.)
Mench predicted the market for shell eggs will
probably move to cage-free. Many people forget that half
of all eggs are used for liquid eggs that are ingredients in
baked goods and other products. She predicts that liquid

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MEAT+ POULTRY | 06.15 | www.meatpoultry.com

egg producers may slowly move to colony housing.
Mench also explained that the study compared the
three systems with the same white hens. The use of
different genetics may affect the performance of a housing
system. People are constantly innovating. A walk through
the trade show clearly showed that equipment companies
are inventing new designs.
The problems in the present aviary system can
probably be fixed. The higher percentages of dirty egg
shells is due to hens laying eggs on the floor. Equipment
innovators will find a way to stop floor eggs, improve air
quality and reduce death losses.

AVIAN FLU FROM MIGRATING BIRDS
The recent outbreak of avian influenza (AI) in turkeys and
other poultry was likely due to manure droppings from
migrating birds. David Soarez and Erica Spackman from
USDA/ARS in Athens, Ga., presented the results of a study
on bird susceptibility to AI. Wild mallard ducks easily
became infected, but they get a very slight illness. In other
words, they are well adapted to AI.
Turkeys require a high dose of the virus to get infected,
but a high percentage of birds die when they get sick.
Keeping AI out of poultry houses is going to get more and
more difficult.
A map in the March 16 Feedstuffs showed that the
major migration routes for wild birds move over major
broiler and laying hen areas in Arkansas, Iowa and
Minnesota. The migratory routes extend up into Canada
and may enable the virus to pass in from Asia. Dale Lauer
with the Minnesota Board of Health told attendees at the
poultry conference that three out of four of the migration
flyways are now infected. The virus will continue to
spread in the flyways.
I fear that disease problems in intensive animal
agriculture may continue. Paul Sundberg told a recent
National Pork Industry Forum that he did not know where
PEDv (Porcine Epidemic Diarrhea virus) came from. He
said, "This is a production disease outside the scope of
USDA." Maybe to stop some of these diseases, we need to
start breeding animals for optimum production instead of
maximum production.
Some producers say we have to feed a hungry world, but
dead piglets and turkeys feed nobody. There is a point where
drastic biosecurity procedures such as filters and baking
trucks may stop working. We may need to breed more hardy
animals, and look at all parts of an integrated system.
D R . T E M P L E G R A N D I N | M E AT P O U LT RY@ S OS L A N D.CO M
http://www.sustainableeggcoalition.org http://www.meatpoultry.com
MEAT+POULTRY - June 2015

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