Since 1996, it has been discussing the use of the vaccine for Marek’s disease in 1 day old broilers. The genetic improvements, before 1996, have supposed a little nutritional disorder (deficiencies of Vitamin B) which was aggravated due to an increase of trichothecenes in feed. This situation coincided with diagnostics of Marek’s disease in broilers. It will be interesting to analyse in depth every single etiology:

1.AVITAMINOSIS GROUP B
Vitamins B constitute a Group of  water soluble substances with different physiologic effects, so its effects will depend on its deficiencies.

1.Avitaminosis B1 in birds produces polyneuritis with asthenia, ataxia, neck twisting, and deformation of the tendons of the toes.
2.Avitaminosis B2 produces paralytic alterations and skin rashes
3.Avitaminosis B6 produces ataxia and the avitaminosis for pantothenic acid presents dermatitic injuries. It must to have into account that this acid is known as an antidermatitic factor in broilers.

It is estimated that current strain of broilers, has physiologic needs 30% bigger than indicated in nutritional tables of reference, so it is possible the appearance of subclinical Avitaminosis by feeding broilers and breeders according these nutritional tables. These subclinical Avitaminosis leads ataxia, polyneuritis and dermatitis.

2. MAREK’S DISEASE
The Marek’s disease is a virosis which presents neuronal injuries in lumbosacral plexus which can be accompanied of injuries in skin or not. It can even appear in younger ages (3-4 weeks old).

3. TRICHOTHECENES

In Veterinaria Digital you will be able to found soon a vast article by Dr. Enrique Hernández about these toxins secreted by fungi of the gender Fusarium.
In order to link this matter with ataxias and avian dermatitis we can mention that presence of trichothecenes in feed is due to an increase of fitopathologies in cultures of cereals occasioned by Fusarium, which is transmitted in raw materials.
Trichothecenes are sesquiterpene which have a necrotising effect by contact on intestine mucosa that affects the absorption of nutrients. Water soluble vitamins are particularly vulnerable as deficient absorption during a few days cause total or partial deficiencies of the same ones.

Contamination by trichothecenes in feed can cause the same symptoms as in Vitamins Group B (ataxias and dermatitis) due to a bad intestinal absorption.

To summarize, in order to face this problem about ataxias and dermatitis in broilers, it is necessary the execution of a precise differential diagnostic. If on the contrary, we want to plan a Health program, simultaneously, we will have to carry out the following measures:
• Inclusion of an already contrasted mycotoxin binder against trichothecenes.
• Reviewing the doses of Vitamins Group B in ration for breeders and broilers having into account the standards of the strains.
• Evaluate titles of antibodies against Marek in vaccinated and non vaccinated farms of the geographical area where the action will be carried out in order to have some criteria about the necessity of incorporating the vaccine to a work plan.