Chris Morrow talks about mycoplasma vaccination in layers
Published:January 18, 2021
Chris Morrow (Bioproperties) commented about the problems that arise from mycoplasma infections in layer farms and explained the benefits of a live mycoplasma vaccination program, including costs and profits.
The vaccine should not be expected to solve the mycoplasma problem if biosecurity measures are not implemented. Cultivation of various age categories in the industry is not possible and such will never give a satisfactorily healthy flock.
serologically m.s positives are vbecoming a common affair in breeders and layers who line long.
flocks which are .
m.g. negative during growing are becoming positive during laying by 30weeks.
antimycoplasma drugs in feed and water are keeping the problem under check. without medication and poor management secondary infections take over and the flock performance is a disaster.
Live vaccines in third week with no medication prior and after vaccination are not found to be very effective. killed vaccines administered are preventing the damage when the exposure is heavy and the climate changes are drastic.
biosecurity to keep the secondary infections low and regular medication seems be a better way of dealing the problem.
practical experiences on the serology and effectiveness of the vaccines are welcome. opinions of the vaccine manufacturers are well known.
The vaccines have different kinetics with serology and PCR
MSH tends to increase in pan species PCR to 100% about 8 weeks post vaccination and stay high for the life of the bird. DIVA PCRs are less sensitive than pan species PCRs in general.
ts-11 initially increases in pan MG PCRs to about 4 week post vaccination peaking at 40% and then decrease again to rise as the birds come into lay and peak higher to nearly 100% PCR. Again DIVA PCRs are less sensitive.
Serology can remain flat negative till the birds are coming into lay and then rising - SErology is useless for monitoring vaccinated flocks - PCR is the only test that will give definitive answers.
So without knowing the timing of your testing it could be normal.
But you could be not vaccinating effectively and here you must consider antibiotic usage, cold chain and application (must be eyedrop), immunosuppression, etc. Are you having any clinical signs?
1) you should control MG and MS with the same strategy. (freedom, vaccination, or antibiotics) 2) you should source replacement that is mycoplasma free 3) if your farm is multiage then you should rear stock remotely (2 km away from other poultry) and vaccinate them for the challenges they will get when they are moved to the multiage site. 4) Use live MG and MS vaccine - one dose. Don't use killed vaccines - don't worry about serology after vaccination and don't give the birds antibiotics unless they have clinical signs and if they do have clinical signs, get a diagnosis - DIVA PCR
How many shots of Live vaccine or killed in layers and at what age and which vaccine you will prefer Dr. Morrow specially for MG control as it is a problem in Pakistan
If you remember you chaired session in WVPAC 2007 Beijing Where i presented on gentamicin toxicity it was my first international presentation
If you want more details about vaccination
http://www.bioproperties.com.au/!Pages/Publications/Documents/DOC-Bulletin-2020-01.pdf
If you want information on the Antibiotic sensitivity survey in Asia in MG and MS
Morrow CJ, Kreizinger Z, Achari RR, Beko K, Yvon C, Gyuranecz M. Antimicrobial susceptibility of pathogenic mycoplasmas in chickens in Asia. Vet Microbiol. 2020 Nov;250:108840. doi: 10.1016/j.vetmic.2020.108840. Epub 2020 Sep 19. PMID: 33068825.
Do you think Using live Ms vaccine fails in areas where biosecurity is poorly practiced, impossibility to finding Ms and Mg free day old chick layers, over vaccination for Newcastle disease that leads to severe vaccination reaction followed by using antibiotics, multiple rearing of layer Pullets and producing layers in the same area?
Is Ms live vaccinated flock getting PCR positive during rearing and production? If yes, that would be problematic in my country as we do not have laboratory equipped with sequencer to differentiate vaccinated from vaccinated infected flocks !!
Also it is so difficult to not to use antibiotics in Ms vaccinated flocks due to post vaccination reaction to other respiratory vaccines!
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