Now is the time to review your herd Johne’s programme.

Why should I be concerned about Johne’s?

As herdowners we cannot control the weather or milk price fluctuations but we must ensure that we guard against poor production and fertility performance.
Johne’s once established in a herd reduces milk yield, reduces fertility and leads to premature culling, also reduced income from incalf heifer sales.
Key Point
The estimated prevalence of Johne’s in Ireland is 20%, 1 in every 5 herds infected.
How is Johne’s different to the other diseases we are more familiar with?
If I visited your farm today the 1st of August with a high dose of IBR any of you not vaccinating would see the signs in 12 -15 days, by the 12-15th of August you would have cow, heifers and calves coughing, snotty noses and some running high temperatures, depressed and sick also the cows would have reduced milk yield for a short period. 
Johne’s is different, if I visited your farm today the 1st of August with a high dose of Johne’s, the only animals I could infect would be the young calves, especially in the first days, weeks and months of life. Secondly you would not see anything until these animals are 3-5 years of age. 
We now have a disease that is easily picked up by very young calves and older animals are less likely to become infected, secondly it can take 3-5 years for the signs to begin to show.
 In the meantime these animals are spreading the disease to the younger calves without we knowing it - this is often called unseen spread. This unseen spread is the time when Johne’s takes hold and establishes in a herd.
 
What are the signs of Johne’s in a dairy herd?
Even though the cow got infected as a young calf the bacteria stays in the gut cells dormant for 3-5 years. Then when it becomes activated it thickens the wall of the gut, food cannot get absorbed as well as it should, the cow’s immunity is reduced, then the animal does not produce as well as is expected and fertility is also reduced. At this stage most of these cows get culled out of the herd for being not incalf, high cell count or poor producers or for other health reasons, this occurs especially in spring calving herds.  
If the cow is retained in the herd and milked through the winter and gets mated again the following season, we see more signs of Johne’s with the cow now beginning to scour and lose weight initially, even though her appetite is normal.  Often after her dry off period she will recover somewhat and look ok. Then after the stress of calving she will start to struggle again, if she is not culled she will eventually keep scouring and losing weight, with no response to treatment until she pines away. 
If animals are culled because of infertility, poor performance or other diseases, an infected herd may never have cows with the more obvious signs of Johne’s disease.  These herds will just not be able to achieve the target of 500kg of milk solids per cow or the 70-90% six week calving rate.
If I have never seen any signs of Johne’s in my herd, why should I test?
By the time you will see actual signs of Johne’s it is too late - the ball is in the back of the net with the green flag raised!
Is there any treatment for Johne’s?
There is no effective treatment for Johne’s. Vaccination is not available in Ireland for Johne’s.  Prevention is the only option.
How is Johne’s spread? (Can we do a flow chart of this. eg infected cow to calf via colostrum, dung, milk)
Johne’s is spread from an infected cow that picked it up as a calf. When this cow becomes infectious at 3-5 years of age she is shedding Johne’s in her dung, colostrum, milk and maybe across the womb to her calf. A positive cow in the calving shed/pen will be shedding millions of bacteria in her dung, the young calves in that pen will pick it up from the bed and then when the calves begins sucking it will pick it up from the  dirty areas around the udder and dirty teats.  Also the colostrum and milk will contain Johne’s so mixing colostrum and milk from different cows can increase the risk of spread of Johne’s. The most common way that Johne’s is spread in a herd is by the dung, milk and colostrum of positive cows being ingested or fed to young calves, without the herdowner realising that these cows are positive.
Some of the labour saving practices that we are adapting now are favouring the spread of Johne’s in infected herds - group calving accommodation, feeding pooled colostrum and milk to calves and not having very clean calving pens due to the pressure of a 70-90% calving rate in 6 weeks.
How did I get Johne’s in my herd?
The most common way that Johne’s enters a herd is through the purchase of an infected animal either as a calf, incalf heifer, cow or bull from an infected herd. Often the seller at the time may not realise that he is selling an infected animal as he may only realise later that he has an infected herd. 
That purchased animal then has been multiplying it within the herd since it was purchased. 
Other ways are getting colostrum, milk or slurry from infected farms and young calves being fed or ingesting it. 
What is the first step in establishing my herd’s Johne’s status?
Initially testing all the animals over 2 years of age which is all the milking herd is a very good starting place. You can do this either through the individual sample that is taken at the time of milk recording or by taking blood samples at the time of your TB test.
The milk recording sample is very convenient and cost effective, it costs €5.50 for two tests on each cow. 
In addition to testing AHI has developed a nice risk assessment programme that your vet can carry out for your farm.
Are the available tests accurate and is there a difference between individual milk and blood?
The tests that are available are more than adequate to identify that the herd is infected or not.  However we need repeated tests on individual cows to establish their status. There is no difference between the milk tests offered by Munster group and blood testing.  Currently we have a lot of herds addressing Johne’s successfully with the current tests and changing their calf rearing practices.
If I have positives in my test, what do I do? 
If you have one or more positives the likelihood is that the herd is infected. The characteristics of the test are that we know the positives are positive, but the negatives may go positive in the future if they have been infected as a calf.  You cannot change or treat the cows you have but you can ensure the replacements born in 2016, 2017, 2018 etc. can be kept as clean as possible. The quicker you deal with Johne’s the quicker you will reduce down the level in your herd, ignoring it will allow it to continue to spread. 
Protect the 2016 replacements from dung, milk and colostrum from positive cows
Cull all known positives and suspects after consultation with your vet (usually 1-4 cows).
This will ensure their dung is not on the coats of other cows or in the calving boxes.
Have clean well bedded calving pens and snatch the heifer calf immediately before anything enters her mouth and put her in the calf rearing shed.
Give her 3-4 litres of clean colostrum in the first 2-6 hours of birth from her own mother.
Then the replacements need to go on milk replacer as we cannot be confident that the remaining cows are negative.
Doing nothing is not an option as Johne’s will continue to spread in the herd. It is much better to deal with Johne’s and to protect the 2016 replacements. 
Salmonella control.
In this dairying area control of salmonella is very important. The two vaccines that I would recommend to all dairy herdowners to do are leptospirosis and salmonella.
Vaccination is the main method of control for salmonella. Other methods are biosecurity, management and maintaining a closed herd to avoid the purchase of a carrier animal.
For spring calving herds the most opportune time to vaccinate is the first week of September. All the cows and incalf heifers need to be vaccinated. 
It is also advisable to begin the vaccination for the 2015 calves this Autumn, by giving them their primary and booster. Then next September 2016 you only need to boost them with one dose of the vaccine.
The advantage of vaccinating the 2015 calves this Autumn is that it will reduce the carrier state in the heifers, next September 2016 they will only need one dose and they are covered by vaccination till September 2016. Your incalf heifers are now at this point not covered until two weeks after they have received their second vaccine, unless they were vaccinated last Autumn. 
Recent work between the veterinary college and moorepark demonstrated that in endemic infected unvaccinated herds that have not experienced an outbreak, profits per cow were reduced by €77/cow on average at a milk price of 24c/litre. Profits in vaccinated herds were €68/cow greater than in unvaccinated exposed herds. 
Bovivac S is the only licensed Salmonella vaccine licensed for use. 
Dosage
Two 5ml under the skin twice 3 weeks apart. Boosted within 12 months.  
It is crucial to only allow 3 weeks or 21 days between the two vaccines. 

As herdowners we cannot control the weather or milk price fluctuations but we must ensure that we guard against poor production and fertility performance.Johne’s once established in a herd reduces milk yield, reduces fertility and leads to premature culling, also reduced income from incalf heifer sales.

Key Point: The estimated prevalence of Johne’s in Ireland is 20%, 1 in every 5 herds infected.

How is Johne’s different to the other diseases we are more familiar with?

If I visited your farm today the 1st of August with a high dose of IBR any of you not vaccinating would see the signs in 12 -15 days, by the 12-15th of August you would have cow, heifers and calves coughing, snotty noses and some running high temperatures, depressed and sick also the cows would have reduced milk yield for a short period.
Johne’s is different, if I visited your farm today the 1st of August with a high dose of Johne’s, the only animals I could infect would be the young calves, especially in the first days, weeks and months of life. Secondly you would not see anything until these animals are 3-5 years of age.
We now have a disease that is easily picked up by very young calves and older animals are less likely to become infected, secondly it can take 3-5 years for the signs to begin to show.
In the meantime these animals are spreading the disease to the younger calves without we knowing it - this is often called unseen spread. This unseen spread is the time when Johne’s takes hold and establishes in a herd. 

What are the signs of Johne’s in a dairy herd?

Even though the cow got infected as a young calf the bacteria stays in the gut cells dormant for 3-5 years. Then when it becomes activated it thickens the wall of the gut, food cannot get absorbed as well as it should, the cow’s immunity is reduced, then the animal does not produce as well as is expected and fertility is also reduced. At this stage most of these cows get culled out of the herd for being not incalf, high cell count or poor producers or for other health reasons, this occurs especially in spring calving herds.
If the cow is retained in the herd and milked through the winter and gets mated again the following season, we see more signs of Johne’s with the cow now beginning to scour and lose weight initially, even though her appetite is normal.  Often after her dry off period she will recover somewhat and look ok. Then after the stress of calving she will start to struggle again, if she is not culled she will eventually keep scouring and losing weight, with no response to treatment until she pines away.
If animals are culled because of infertility, poor performance or other diseases, an infected herd may never have cows with the more obvious signs of Johne’s disease.  These herds will just not be able to achieve the target of 500kg of milk solids per cow or the 70-90% six week calving rate.

If I have never seen any signs of Johne’s in my herd, why should I test?

By the time you will see actual signs of Johne’s it is too late - the ball is in the back of the net with the green flag raised!

Is there any treatment for Johne’s?

There is no effective treatment for Johne’s. Vaccination is not available in Ireland for Johne’s.  Prevention is the only option.

How is Johne’s spread? (Can we do a flow chart of this. eg infected cow to calf via colostrum, dung, milk)

Johne’s is spread from an infected cow that picked it up as a calf. When this cow becomes infectious at 3-5 years of age she is shedding Johne’s in her dung, colostrum, milk and maybe across the womb to her calf. A positive cow in the calving shed/pen will be shedding millions of bacteria in her dung, the young calves in that pen will pick it up from the bed and then when the calves begins sucking it will pick it up from the  dirty areas around the udder and dirty teats.  Also the colostrum and milk will contain Johne’s so mixing colostrum and milk from different cows can increase the risk of spread of Johne’s. The most common way that Johne’s is spread in a herd is by the dung, milk and colostrum of positive cows being ingested or fed to young calves, without the herdowner realising that these cows are positive.
Some of the labour saving practices that we are adapting now are favouring the spread of Johne’s in infected herds - group calving accommodation, feeding pooled colostrum and milk to calves and not having very clean calving pens due to the pressure of a 70-90% calving rate in 6 weeks.

How did I get Johne’s in my herd?

The most common way that Johne’s enters a herd is through the purchase of an infected animal either as a calf, incalf heifer, cow or bull from an infected herd. Often the seller at the time may not realise that he is selling an infected animal as he may only realise later that he has an infected herd.
That purchased animal then has been multiplying it within the herd since it was purchased.
Other ways are getting colostrum, milk or slurry from infected farms and young calves being fed or ingesting it.

What is the first step in establishing my herd’s Johne’s status?

Initially testing all the animals over 2 years of age which is all the milking herd is a very good starting place. You can do this either through the individual sample that is taken at the time of milk recording or by taking blood samples at the time of your TB test.
The milk recording sample is very convenient and cost effective, it costs €5.50 for two tests on each cow.
In addition to testing AHI has developed a nice risk assessment programme that your vet can carry out for your farm.

Are the available tests accurate and is there a difference between individual milk and blood?

The tests that are available are more than adequate to identify that the herd is infected or not.  However we need repeated tests on individual cows to establish their status. There is no difference between the milk tests offered by Munster group and blood testing.  Currently we have a lot of herds addressing Johne’s successfully with the current tests and changing their calf rearing practices.
If I have positives in my test, what do I do?

If you have one or more positives the likelihood is that the herd is infected. The characteristics of the test are that we know the positives are positive, but the negatives may go positive in the future if they have been infected as a calf.  You cannot change or treat the cows you have but you can ensure the replacements born in 2016, 2017, 2018 etc. can be kept as clean as possible. The quicker you deal with Johne’s the quicker you will reduce down the level in your herd, ignoring it will allow it to continue to spread.
Protect the 2016 replacements from dung, milk and colostrum from positive cows
Cull all known positives and suspects after consultation with your vet (usually 1-4 cows).
This will ensure their dung is not on the coats of other cows or in the calving boxes.
Have clean well bedded calving pens and snatch the heifer calf immediately before anything enters her mouth and put her in the calf rearing shed.
Give her 3-4 litres of clean colostrum in the first 2-6 hours of birth from her own mother.
Then the replacements need to go on milk replacer as we cannot be confident that the remaining cows are negative.

Doing nothing is not an option as Johne’s will continue to spread in the herd. It is much better to deal with Johne’s and to protect the 2016 replacements. 


Salmonella control.

In this dairying area control of salmonella is very important. The two vaccines that I would recommend to all dairy herdowners to do are leptospirosis and salmonella.
Vaccination is the main method of control for salmonella. Other methods are biosecurity, management and maintaining a closed herd to avoid the purchase of a carrier animal.
For spring calving herds the most opportune time to vaccinate is the first week of September. All the cows and incalf heifers need to be vaccinated.
It is also advisable to begin the vaccination for the 2015 calves this Autumn, by giving them their primary and booster. Then next September 2016 you only need to boost them with one dose of the vaccine.
The advantage of vaccinating the 2015 calves this Autumn is that it will reduce the carrier state in the heifers, next September 2016 they will only need one dose and they are covered by vaccination till September 2016. Your incalf heifers are now at this point not covered until two weeks after they have received their second vaccine, unless they were vaccinated last Autumn.
Recent work between the veterinary college and Moorepark demonstrated that in endemic infected unvaccinated herds that have not experienced an outbreak, profits per cow were reduced by €77/cow on average at a milk price of 24c/litre. Profits in vaccinated herds were €68/cow greater than in unvaccinated exposed herds.
Bovivac S is the only licensed Salmonella vaccine licensed for use.

Dosage
Two 5ml under the skin twice 3 weeks apart. Boosted within 12 months.
It is crucial to only allow 3 weeks or 21 days between the two vaccines. 

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