Saturday 26 May 2012
Headlines
Did you find this story interesting? (0) (0)
22/11/2004
Infectious Bronchitis vaccination in lay - is it necessary?
Previous articles in the Ranger have discussed Infectious Bronchitis virus (IBV) and its variants. This disease was first identified in America in the 1930s and still causes problems in chicken flocks worldwide and probably always will! The primary target organ affected by IB virus is the respiratory tract but the virus can also cause kidney damage and can damage the oviduct affecting egg production and shell quality in laying flocks.
Since the last century great progress has been made in controlling IB and IB variant infection. Many vaccines have been developed to protect chicken flocks against infection with these viruses.
There are two types of IB vaccine:
Live vaccines – these are modified versions of original field viruses which do not cause disease but stimulate the birds immune system to produce protective antibodies against infection. Live vaccines are usually sprayed onto the birds to introduce the vaccine into the respiratory system or may be given in drinking water. Live vaccines provide local immunity in the respiratory tract of the bird and help to ’prime’ the immune system to respond better to dead vaccine.
Dead (inactivated) vaccines – these vaccines are usually given by injection. This type of vaccine contains field strain virus which has been killed so it cannot replicate in the bird. The bird’s immune system responds by producing antibodies to protect against future challenge by IB viruses. They are usually part of multi-component vaccines, also protecting against ND and EDS.
Most laying flocks in the UK receive a very full program of IB and IB variant vaccines during the rearing period. Birds receive both ’classic’ IB type vaccine and IB variant vaccines, with the timing of vaccination planned to give the best protection to the bird both in the rearing period and into lay.
Despite these measures IB and IB variant challenges still remain a significant problem in laying flocks in the UK. The commonest problem seen is the economic effect caused by drops in egg production and associated shell quality changes but occasionally flocks may show an increase in mortality associated with IB challenge in lay.
So why do we continue to see problems in lay when birds have been vaccinated in rear?
This can happen for various reasons:
Poor administration of vaccine
Poor or variable response to vaccine
Challenge by IB variant not covered by vaccination program – IB has the uncanny knack of regularly throwing up new variants which may require a rethink on your vaccination strategy.
Waning of immunity so birds become vulnerable to challenge in lay
What can we do to address these problems?
Pullet rearers will often take blood samples from flocks in rear to check that birds have responded to live vaccination and are well ’primed’ to respond to the subsequent dead vaccination.
Although no IB vaccination program can give 100% protection throughout lay, as we do not live in a perfect world, there is a lot we can still do to make sure that the flock immunity is as good as we can get.
One way to try and assess the immunity level in our flocks is to look at blood samples from the flock at various times in the life of the flock. This helps to build up a picture of how well, and how ’evenly’ the birds have responded to their vaccination program, as well as indicating if they have been challenged by other specific variants. This can help us to judge if the flock may need additional vaccine in lay.
Should I vaccinate in lay?
There is no one vaccine program which is right for all flocks in lay. Whether you use additional IB and IB variant vaccine in your laying flock depends on the history of your own flocks and site. A strategy of blood sampling can help in that planning.
If you have a single age site, fairly remote from other poultry, and have never seen IB problems in lay then your flock may not need any additional vaccination in lay.
If, however, you have had IB problems in previous flocks you may wish to give additional IB vaccine in lay to boost immunity – particularly the ’local’ immunity in the respiratory tract.
The decision whether to vaccinate in lay or not is not straightforward as many different factors need to be taken into account. It is best to discuss this with your veterinary surgeon as to what is the best approach for your flock taking into account the previous history of your site, vaccination history of your flock, and the risk in your area.
Although IB vaccination in lay is commonly done in UK flocks it must be remembered that none of the available live IB or IB variant vaccines used in this way are licensed for use in laying birds. Vaccination in lay is unlikely to cause problems but you should ensure that you do not use a vaccine in lay unless the bird already has a strong IB priming via the rearing programme.
How should I give vaccines in lay?
If you decide to vaccinate a flock in lay you have to consider timing – how often, and method of administration. Spraying vaccine is likely to be the most effective route as the vaccine virus is applied to the respiratory tract but many producers have found that drinking water administration can also work well.
Vaccine manufacturers can offer advice about the most suitable type of spray applicator for their vaccines and may be willing to help producers by giving a demonstration of vaccine application on the farm.
If you are going to spray vaccinate for the first time you may want to have a ’dummy’ run with just water in the sprayer to make sure that you have calculated the right amount of water to dilute the vaccine in to be able to spray the whole flock. You also need to consider the right time in the day to vaccinate as the birds need to be all together on the slats. You should aim to fit the vaccination in without disrupting the birds’ routine too much. In sheds with additional fan ventilation this will need to be turned off while vaccination is in progress.
If giving vaccine in drinking water this should be done carefully following the manufacturers’ instructions to make sure that the live vaccine reaches the bird.
How often should I vaccinate?
’Top-up’ live vaccination in well vaccinated birds will only produce short term added protection in the respiratory tract against further IB challenges. Some producers may vaccinate every 6 to 8 weeks, some every 12 weeks and some only once or twice during the laying period. Some programs may involve giving only one vaccine each time, others may use two different vaccines given together or alternate between vaccines for each administration. Much depends on the number of flocks on site, their age spread and the challenges expected.
How do I know I have done any good?
You should always assess the success or otherwise of any vaccination program so it can be amended if necessary for the next flock. This can be done by blood sampling and a straightforward assessment of flock performance (egg numbers, egg colour, seconds, rejects etc).
Conclusions
As so frequently discussed in these columns, ’prevention rather than cure’ is the key to avoiding commercial loss through infections waiting to attack your flock. IB vaccination in lay can be a useful ’top-up’ tool in the control of egg drops and shell quality problems, but every farm is different so the requirements will vary.
Finally, you should always remember that the problem you are seeking to address may not be due to IB – many egg production drops put down to IB challenge are due to some other problem entirely!
Since the last century great progress has been made in controlling IB and IB variant infection. Many vaccines have been developed to protect chicken flocks against infection with these viruses.
There are two types of IB vaccine:
Live vaccines – these are modified versions of original field viruses which do not cause disease but stimulate the birds immune system to produce protective antibodies against infection. Live vaccines are usually sprayed onto the birds to introduce the vaccine into the respiratory system or may be given in drinking water. Live vaccines provide local immunity in the respiratory tract of the bird and help to ’prime’ the immune system to respond better to dead vaccine.
Dead (inactivated) vaccines – these vaccines are usually given by injection. This type of vaccine contains field strain virus which has been killed so it cannot replicate in the bird. The bird’s immune system responds by producing antibodies to protect against future challenge by IB viruses. They are usually part of multi-component vaccines, also protecting against ND and EDS.
Most laying flocks in the UK receive a very full program of IB and IB variant vaccines during the rearing period. Birds receive both ’classic’ IB type vaccine and IB variant vaccines, with the timing of vaccination planned to give the best protection to the bird both in the rearing period and into lay.
Despite these measures IB and IB variant challenges still remain a significant problem in laying flocks in the UK. The commonest problem seen is the economic effect caused by drops in egg production and associated shell quality changes but occasionally flocks may show an increase in mortality associated with IB challenge in lay.
So why do we continue to see problems in lay when birds have been vaccinated in rear?
This can happen for various reasons:
Poor administration of vaccine
Poor or variable response to vaccine
Challenge by IB variant not covered by vaccination program – IB has the uncanny knack of regularly throwing up new variants which may require a rethink on your vaccination strategy.
Waning of immunity so birds become vulnerable to challenge in lay
What can we do to address these problems?
Pullet rearers will often take blood samples from flocks in rear to check that birds have responded to live vaccination and are well ’primed’ to respond to the subsequent dead vaccination.
Although no IB vaccination program can give 100% protection throughout lay, as we do not live in a perfect world, there is a lot we can still do to make sure that the flock immunity is as good as we can get.
One way to try and assess the immunity level in our flocks is to look at blood samples from the flock at various times in the life of the flock. This helps to build up a picture of how well, and how ’evenly’ the birds have responded to their vaccination program, as well as indicating if they have been challenged by other specific variants. This can help us to judge if the flock may need additional vaccine in lay.
Should I vaccinate in lay?
There is no one vaccine program which is right for all flocks in lay. Whether you use additional IB and IB variant vaccine in your laying flock depends on the history of your own flocks and site. A strategy of blood sampling can help in that planning.
If you have a single age site, fairly remote from other poultry, and have never seen IB problems in lay then your flock may not need any additional vaccination in lay.
If, however, you have had IB problems in previous flocks you may wish to give additional IB vaccine in lay to boost immunity – particularly the ’local’ immunity in the respiratory tract.
The decision whether to vaccinate in lay or not is not straightforward as many different factors need to be taken into account. It is best to discuss this with your veterinary surgeon as to what is the best approach for your flock taking into account the previous history of your site, vaccination history of your flock, and the risk in your area.
Although IB vaccination in lay is commonly done in UK flocks it must be remembered that none of the available live IB or IB variant vaccines used in this way are licensed for use in laying birds. Vaccination in lay is unlikely to cause problems but you should ensure that you do not use a vaccine in lay unless the bird already has a strong IB priming via the rearing programme.
How should I give vaccines in lay?
If you decide to vaccinate a flock in lay you have to consider timing – how often, and method of administration. Spraying vaccine is likely to be the most effective route as the vaccine virus is applied to the respiratory tract but many producers have found that drinking water administration can also work well.
Vaccine manufacturers can offer advice about the most suitable type of spray applicator for their vaccines and may be willing to help producers by giving a demonstration of vaccine application on the farm.
If you are going to spray vaccinate for the first time you may want to have a ’dummy’ run with just water in the sprayer to make sure that you have calculated the right amount of water to dilute the vaccine in to be able to spray the whole flock. You also need to consider the right time in the day to vaccinate as the birds need to be all together on the slats. You should aim to fit the vaccination in without disrupting the birds’ routine too much. In sheds with additional fan ventilation this will need to be turned off while vaccination is in progress.
If giving vaccine in drinking water this should be done carefully following the manufacturers’ instructions to make sure that the live vaccine reaches the bird.
How often should I vaccinate?
’Top-up’ live vaccination in well vaccinated birds will only produce short term added protection in the respiratory tract against further IB challenges. Some producers may vaccinate every 6 to 8 weeks, some every 12 weeks and some only once or twice during the laying period. Some programs may involve giving only one vaccine each time, others may use two different vaccines given together or alternate between vaccines for each administration. Much depends on the number of flocks on site, their age spread and the challenges expected.
How do I know I have done any good?
You should always assess the success or otherwise of any vaccination program so it can be amended if necessary for the next flock. This can be done by blood sampling and a straightforward assessment of flock performance (egg numbers, egg colour, seconds, rejects etc).
Conclusions
As so frequently discussed in these columns, ’prevention rather than cure’ is the key to avoiding commercial loss through infections waiting to attack your flock. IB vaccination in lay can be a useful ’top-up’ tool in the control of egg drops and shell quality problems, but every farm is different so the requirements will vary.
Finally, you should always remember that the problem you are seeking to address may not be due to IB – many egg production drops put down to IB challenge are due to some other problem entirely!
No Comments
Nobody has posted any comments on this story.
|
Farming items for Sale
|
Case mxu130 xline, 4wd - Telford(GBP 19950)
Case 155puma - Chippenham(GBP 61500)
John Deere 3310 - Thame
(Price on Application)
(Price on Application)
FORD NEW HOLLAND 8340 4WD - TEMPLECOMBE(GBP 8000)
JCB 8250 - Chippenham(GBP 96938)
Related News
Infectious bronchitis (IB) – does a conventional vaccination programme give us adequate pr - 05 May 2006This was the question posed recently by a Ranger reader and I am sure echoes the concerns of many producers, even though we have discussed the ongoing...
Infectious bronchitis - 05 May 2007Today, as ever, if you ask any producer to name the most significant cause of egg production problems, IB is still likely to top the charts, being riv...
Infectious Bronchitis — variations on a theme - 05 May 2006Infectious bronchitis (IB) was first described in 1931 in the USA as a respiratory disease of chicks. In the 1950’s egg production and egg quali...
New Can-Am ATV riding gear range - 30 Jan 2007NEW CAN-AM ATV RIDING GEAR RANGE The new Can-Am(T) clothing range, designed especially for the ATV rider, is available from authorised Can-Am deale...
Pembrokehshire farmers meet local AM - 22 Nov 2007"Farmgate beef and lamb prices need to increase substantially to ensure the long term viability of livestock production in Pembrokeshire," Perkin Evan...
FUW welcomes AM's report on Glastir - 03 Mar 2010The Farmers’ Union of Wales today welcomed the conclusions of the Assembly’s rural development sub-committee’s inquiry into the new ...
FUW members tell AM of TB cull delay worries - 15 Sep 2011Farmers’ Union of Wales members in Carmarthenshire expressed their concerns at the Welsh Government’s failure to drive the bovine TB eradi...
Dairy assurance changes necessary for future, says NDFAS - 11 Aug 2004Change because it's needed and not for change's sake - that's the message from the National Dairy Farm Assured Scheme as milk producers ac...
Farm bill: Crop subsidies necessary - 18 Nov 2007With its version of the 2007 farm bill stalled in the U.S. Senate and the Bush administration already threatening a veto of the House version of th...
Beak Trimming - Is it necessary - 27 Mar 2008Sometimes hens feather peck and cannibalise. We have all seen it happen. Do we know why? Sometimes. It is not always clear why some flocks behave ...
