Johnes in sheep

[Northumberland]

With a recent positive johnes result on annual health scren on cull ewes.
Looking for information on the disease.
Adhb have some good info.
Current plan is to not do anything until next back end when all ewe lamb replacements will be kept separate and given the gudair vaccine after weaning.
Then sort enough young fit ewes suitable for breeding replacements then keep these separate on separate farm which will become the designated replacement farm.
Hopeing I have caught it early enough that it will not be too painfull in the remaining terminal flock which will be culled hard for low BCS.
Any ideas welcome
Thanks

 

[GreenerGrass]

We vaccinate, plenty of flocks have it and don't know. No one knows how prevalent but probably fairly bad. How old was your ewe, supposedly if it is affecting younger animals then it is seriously endemic and rife in your flock.

I jab mine with Gudair at the same time as toxovax. Importantly it massively reduces shedding risk, so consider doing whole flock IMO, as the disease is picked up by young lambs and doesn't have to be from their mum. Then do replacements each year. There was one of the NZ lads on here that said after a few years vaccine you can eradicate from your flock, the vaccine is that effective as stopping them going clinical and spreading. ?

Oh just read your separate flock strategy that could work but think it remains prevalent on pasture for a year, so just beware.

 

[Woolless]

No experience on this but would the Moredun Institute have some relevant info online about this?

 

[Global ovine]

The vaccine available in NZ works well, given when weaned ewe lambs are sorted for retention, but it is oil based, therefore those vaccinated sheep must be identified and have their neck lymph glands inspected. If any resultant lesions are found (quite common, even after years) the carcass inspectors go further into the shoulder glands. This adds costs which can be passed onto suppliers and limits the export market opportunities.

Johnnes disease losses were quite common in NZ with up to 5% ewe deaths attributed to this disease in such flocks. The usual pattern of the disease becoming apparent was around mating time where 4 tooth ewes which were deemed good enough to remain in the breeding flock were suddenly found to be turning to skin and bone and often scouring (their pasture intake was near nil, but they drank large quantities of water to get the food through the almost closed sphincter between the small and large intestine). During this stage, such sheep were massive contaminators of pasture with Tuberculosis johnnei bacteria. There bacteria capsulate and have been found to be viable after decades.

Johnnes deaths in NZ have reduced significantly over the last 30 years. Vaccination cannot be given much credit with this. But rather grazing management of sheep certainly can. Over this time more rotational grazing has been employed with flocks fed better over times when previously some feed stress would have occurred. This is seen in the average weight of breeding ewes now much heavier in most flocks and with farmers having contingency plans if the season is not delivering sufficient pasture levels ahead, or greater use of cattle to remove out of control pastures etc.. In summary; NZ farmers are now better all year managers of sheep flocks resulting in much lower incidence of this wasting disease.

 

[Northumberland]

I'm still in death rates of 2% so hopefully have caught this early.
Was a pooled sample for cost effective.
@Global ovine is cattle a must for rotational grazing?
We have ground which is untoppable across the whole block due to stones and topography and really lost control of grass this extreme grass growing summer

 

[Global ovine]

Cattle are not a must to tidy up pasture, but sure do the best job of all grazing species. Like grazing sheep on rotations, the size of the area should fit the mob size (or visa versa) so clean up can be done without penalising the animal performance.

Regarding pooled sample. This tells you that one or more of the contributing animals to the pooled sample was either infected with Johnnes and shedding bacteria, and/or one or more were carriers that may never die of the disease, but keeps shedding bacteria that will infect new animals.
Johnnes is a classic iceberg disease. The sub clinical effect on flock performance can be significant, but not seen, other than a few deaths and dying.
It is important to recognise that most animals that are infected picked up the disease early in life, i.e. before weaning. The gross swelling of the sphincter that blocks the gut only occurs after a period of stress. Hence after the first lamb is weaned is the most common occurrence that can be seen by the 2nd mating. However ewes can go down at any age.

 

[neilo]

I’ve never heard of anyone vaccinating sheep before, just of problems with TB testing of vaccinated cattle.

Out of interest, what does the vaccine cost, and is it an annual job or once in a lifetime?

 

[GreenerGrass]

It's 1ml, and cost me £2.15/jab. It is once for life. Once vaccinated they will show up as positives in tests. But screening limited use in sheep because a negative test result doesn't mean the sheep isn't infected.

 

[Northumberland]

What's the benifit of vaccinating ewes if it's mostly picked up by lambs under 6 month of age?

 

[GreenerGrass]

What's the benifit of vaccinating ewes if it's mostly picked up by lambs under 6 month of age?

If they don't shed it... the lambs don't pick it up...