Diseases and disease eradication in Norwegian goats
In Norway we now have 6 breeds of goats. The three main breeds are Norwegian milking goat, cashmere and mohair, with the Norwegian milking goat the far most abundant. There are about 600 herds with 45 000 milking goats of a total of about 70 000 divided in 1400 herds. It has long ago been recognized that there are big problems with diseases in the goats.
We have seen a lot of respiratory illnesses in kids and also in older animals. Enterotoxemia is a problem in some herds, abortions is probably the most serious illness when it appears, but the causes of abortion is very seldom confirmed.
Of the known infectious diseases CLA is known in most of the herds. Only in northern Norway we have some CLA free herds.
Paratuberculosis is confirmed by bacterial growth from faeces. Between 30 and 40 herds have restrictions because of that. This is a notifiabel disease.
CAE has perhaps become the most important contagious disease during the last 20 years. It is still not notifiabel, and very few countermeasures have been taken until recently. No complete survey has been undertaken to see how many herds have been infected. Last year we tested bulk milk in 387 herds, of which 53 were negative.
For three years there
has been a project going on to try to eradicate the three main illnesses,
CAE, CLA and Johnes disease. It is the health service for goats that
is doing this work. This is led by the Norwegian dairies and the Norwegian
sheep and goat association, the Veterinary Institute and Veterinary College.
The veterinary authority is also participating.
We have started in 22 herds, and have almost completed the eradication in those herds. Even before the project is finished, others who learn how fine this works out, have started on their own. Still more of the farmers are waiting to see if there is a contribution from the state if they start the eradication, and they also want to buy healthy kids. By now we have very few of them, but we expect to have a lot of them soon.
We started out with an incidence of 60-80 % CAEV-positive animals in most of the 22 flocks. Most of these also hade CLA but none had Johnes. Two herds bought healthy herds after sending their sick ones to the abattoir, and then washing, repairing and disinfecting their barns. 13 herds have gone through a process with snatching of kids, feeding cow colostrum and rearing kids in a non-contagious house. After the milking period is over, the old goats have been sent to the slaughterhouse, the barn is cleaned, repaired and disinfected, and then the then pregnant kids have been moved to the old barn. This procedure is copied from the Swiss model, which also is practiced in Sweden and elsewhere.
We are testing the kids before 5 weeks age to see if they have got CAEV-antibodies from their mothers. Then we test at 5 months age, 1 year, 1.5 years and so on until the herds have 5 subsequent negative tests. Then we test once a year two times and then each second year. This regime we will evaluate after some time. We use an ELISA-test. We have the possibility to go a step further with a PCR test, but so far we have not used it.
CLA we are testing before eradication only if there are no clinical cases for the last years. All expected negative herds tested, have in fact been negative. The test is a haemolysin inhibition test.
This year we will start testing 5 months old, presumably healthy, kids with a gammainterferon test for Johnes disease. We have great expectations to this test that we will use in herds with earlier confirmed Johnes disease, but also in herds that are situated not far from these earlier positive herds. If we could use the same method as is being used to eradicate CAE and then hopefully with the gammainterferon test pick out the positive kids before they start shedding bacteria, the possibility to get rid of the disease might be within reach. This is still to be tried out.
We now have about 2500 healthy animals in these herds. The reports from the producers and what we see for ourselves is all very positive. Some of them tell us, that it is almost as starting with a new production; everything has changed. The young goats are producing considerably more. There are reports of goats in their first lactation milking over 900 liters a year. That may not be very impressive to others but is much to be in Norway. The mean production is about 550 l pr goat.
The respiratory diseases have not yet come back, no lameness either, and on pasture the goats are going easily and fast.
We now look forward to
continue the eradication. Lots of farmers have discovered what is going on,
and are eager to get started. We need some economical help from the government;
the dairy industry will continue to support it.
We have started to test more herds, and in this work we cooperate with the veterinary authorities, but the big work is still ahead.
This is a very important
work. It improves animal welfare enormously, it heightens the production and
it makes the life much easier for the farmers.
I hope that in a few years we can give a new report telling about a really healthy goat population in Norway.