Vaccination can go a long way toward the prevention and control of
hemorrhagic enteritis, but it’s no substitute for good management
practices, cautions Dr. John Radu, senior technical service manager with
Intervet/Schering-Plough Animal Health.
Subclinical hemorrhagic enteritis
(HE) has become more of a concern in the turkey industry than classical
HE. The subclinical version, which tends to strike birds 6 to 12 weeks
of age, leads to immunosuppression and mild enteritis. Damage to the gut
wall allows Escherichia coli to penetrate the bloodstream, and
immunosuppression reduces the bird's ability to fight off the infection.
Prevention is key
There
are no good treatments for HE, so the best approach is to prevent the
disease through good management and proper vaccination, Radu advises.“I
emphasize proper vaccination,†Radu says, “because it’s been theorized
that if HE vaccines are given improperly or administered at the wrong
time, the result is suboptimal immunity, which allows subclinical HE to
occur.â€
Vaccination
Turkeys
should be vaccinated against HE by 6 weeks of age, before they are moved
to the grower/finisher barn, Radu says. The exact age to vaccinate
depends on the maternal antibody levels passed on to poults and the
timing of field challenge by the HE virus, he continues. Poults from
breeders with moderate levels of HE antibodies should not be vaccinated
before 4 weeks of age because levels of maternal antibodies may
interfere with the vaccination response, he says.
“In a situation of early field challenge,
these poults should be vaccinated at 4 weeks of age and again at 5 weeks
of age, but poults from breeders with moderate levels of HE antibodies
that are challenged at a later age may only need one vaccination around 5
weeks of age,†Radu says.
Print
Tell friend
Top
