What does Vaccination do?

[ilovemydog]

I buy chicks from ideal-poultry and Murray Mcmurray Hatchery. I have done this for 3 years but never vaccinated. I always sell my birds to make a profit. Could i get more money if i vaccinated them? Also exactly what is Marek's disease? Is it a good idea if i have a bunch of different birds from these 2 different hatcheries? Give me some advice and information on what i should do thank you.

 

[mnferalkitty]

Mareks is a type of tumor disease the vaccination prevents the chickens from getting the tumors but does not prevent the disease if a chicken has mareks it will still be a carrier of it