Egg Industry - March 2018 - 8
8 ❙ EggIndustry
Are cage-free layers healthier?
producers building heated concrete floors in their houses.
Until recently, there was not an approved treatment available in the U.S., but a product was approved in January
2018 for use in pullets and hens in lay.
Organic flocks will not be able to benefit from this
new treatment. Some producers have included diatomaceous earth, oregano or other essential oils in rations to
help control roundworms.
Good vaccination programs have been generally successful in reducing the impact of Mycoplasma gallisepticum and
vaccinal Infectious Larygnotracheitis. There are many vaccine choices for both diseases - vectored vaccines, mild and
stronger strains that allow producers to choose a vaccine appropriate for the disease challenge. Vaccine application is extremely important for these products, and many are applied
individually to ensure needed flock immunity is established.
Several diseases that merit continued research and monitoring were reported as emerging or recurring in cage-free
layers. Dr. Dan Wilson of Wilson Veterinary Co.
observes that the egg industry needs time to draw
any solid conclusions on emerging pathogens.
"Due to the long egg layer production cycle and lack of
facilities to do controlled trials, we must rely on field experience to evaluate the impact of emerging or re-emerging viruses, bacteria, protozoal and parasitic diseases. In
the field, we also have many variables, such as age, bird
strain, housing systems, feed and management, which further complicate our evaluation."
Gallibacterium anatis is increasingly identified as
an important secondary, and perhaps at times primary,
pathogen causing septicemia. It is commonly isolated
from the upper respiratory and lower reproductive tracts
of healthy birds - and manifests itself with lesions in
both areas very similar to E. coli. Many veterinarians
feel this organism is responsible for reduced egg production and higher mortality. To date, this disease has been
primarily observed in the Southeast where mortalities
over 1 percent a week have been noted. The bacterium
quickly develops resistance to antibiotics, and no vaccines are available in the U.S.
www.WATTAgNet.com ❙ March 2018