We have Marek’s. Our first birds were hatched from eggs and vaccinated with the cells free vaccine by us. I believe this is the vaccine that GF uses - no Marek’s losses yet from this group at one year old. Next two groups were chicks purchased from an NPIP certified, well known local breeder who does not believe in vaccination. Lost several 2-4 wk chicks (no necropsy) a 4 mo cockerel and point of lay pullet from the first group from this breeder. Cockerel was first official Marek’s diagnosis, pullet also confirmed. At the same time, we were losing separately housed 2 mo chicks from same breeder - coccidiosis secondary to Marek’s, then just Marek’s cancer when coccidiosis under control. Lost almost all of this second breeder group at 2 mo, rest at point of lay.
We are almost one year out now. Survivors appear healthy. We have broody hens and wanted to add within our flock. I got the more effective, cell-associated Rispens vaccine, which is quite the pain, and vaccinated our eggs in ovo at 18 days. Hens hatched eggs. Those chicks are now 2.5 mo old, no signs yet. Another group of chicks is 3 weeks old. Also ordered chicks from the Chick Hatchery, because they use the Rispens vaccine. Those chicks were put with broody less than 48 hr after vaccination. No losses yet but all of our chicks from this year are still young. If most make it a few months past point of lay, I’ll consider a success our little experiment in Rispens vaccination but early exposure to flock and its Mareks.
The biggest impact for us has been that we no longer sell or give away birds since the diagnosis. Overall, Marek’s has been a bummer and the source of a lot of tears, but something we can live with. Best of luck with your flock!
