My Mareks Wisdom

There are 2 things I have learned about Mareks Disease for the past 15 years:

1. The primary breeders and hatcheries have a lot to do with your birds contacting the disease, and

2. The disease seemed to be mutating that you need more potent vaccines to provide protection for your birds (although this could be caused by # 1 too!).

I have seen so many flocks in my life and have encountered this disease many times and in many places. This disease is really terrible because it affects the birds when the farmers have spent substantial costs already (disease seen from 3 wks to 4 months old) plus it is so contagious that if you decide not to vaccinate your flock, the chances of it landing the disease is higher than the Lakers getting its three-peat in 2011!

Explaining how I arrived at the 2 conclusions I mentioned above is simple. First, I have seen layer and breeder strains which were doing well against the disease for so long until the primary breeders came up with new bird strain which according to them performs better in production. They will market it so well that the commercial hatcheries and individual farmers try it with eagerness only to find out in a couple of months that a lot of their grown pullets dying and exhibiting the pathognomonic sign of unilateral leg paralysis! The culpability of the breeder and hatchery was undeniable because of the magnitude of farmers affected, plus these birds were supposedly protected straight from the hatchery (since the vaccine is given from the hatchery).

Another lesson I saw concerning this disease was the seemingly mutating disease continuously trying to outsmart the vaccine manufacturers. In the mid-nineties, hatcheries were sleeping soundly with the SB1 vaccine strain combating the field virus. Then the actual no. of birds in a flock showing the signs increased and the manufacturers came up with the HVT strain. And then, they began advising that the SB1 had to be combined with the HVT strain to effectively protect the chicks from the disease and true enough, they indeed got some protection. But, in a couple of years again, when cases started to increase again, the Rispens strain of vaccine came out, which later on needed to be combined with the previous strains for better efficacy against the virus. WHEW!!! Which do you think acts fast, the virus mutation or the primary breeders?

I have nothing against the primary breeders because I believe that they are trying to develop their breeds in pursuit of better productivity. Maybe, they just lack the patience to wait for the standard no. of breed testing years before they release any new products to the market. Or maybe the disease is really so wise that it mutates so fast countering the speed of the vaccine manufacturers. NAH! My better judgement leans toward # 1!. However, I also believe that there are more responsible breeders who observe proper protocols in breed selection and do not have this kind of breed mess. In addition, I believe that even the chicken hobbyists who have several chickens at their backyards, are also culpable for the apparent increase in Mareks predisposition. Some breeds are born with inherent strong resistance to the disease but with the pairings done without back-up knowledge of breed genetics, the off springs are unfortunately becoming more vulnerable to Mareks.

At any rate, 3 indisputable Mareks facts as of late are:

1. It is really ubiquitous, meaning IT IS EVERYWHERE, esp where commercial chicken production is being done. Remember that this disease gets transmitted via feather dander or poultry dust which flies with the air!

2. The disease still has no cure. Sorry but if you see the disease ravaging a big portion of your flock, just condemn it and move on. I say a big portion because sometimes, a couple of birds might have inadvertently missed proper vaccination and got the disease but the rest of the flock is protected;

3. Flocks have to be vaccinated straight from the hatchery (or before reaching the farm) because somehow it needs to set in prior to challenge.

These things I have related are my personal observations and opinions regarding this disease and in no way directed to malign anybody or any breed for this matter.

Copyright Poultry Doc www.freepoultryconsultant.host56.com June 25, 2010