Acute Fluke

Last year we were talking about the developing problems with liver fluke and the difficulties in diagnosing the disease. Since then there have been a number of farms who have suffered acute fluke in sheep, and some goats. The Veterinary Laboratories Agency has been reporting significant losses. Sheep with acute fluke often seem to be in good condition, they don’t scour or have swellings under their jaw, the usual history is that they have been found dead. Closer examination may reveal pale membranes around the eye. This disease occurs because so many developing fluke have reached the liver they disrupt the structure of the organ and cause significant haemorrhage into the abdomen. Some animals that have a smaller fluke burden may behave as if they have twin lamb disease, they will have a poor appetite and may go off their back legs.

Extra Treatments

It would seem that sheep have picked up fluke well into November last year and that the developing larvae have survived some of the fluke treatments that were administered early in the autumn. Since the frosty weather in December no further infections would have started, you are only safe if treatments have been given after December. If there are any doubts it might be wise to have some faeces samples checked or to use a fluke drench on the whole flock. From faeces it is either a negative or a positive report for fluke, the actual numbers in the sample are not very significant as the adult fluke lay eggs intermittently. It is usually better if you can gather samples from six to ten sheep. We can then mix these together and process them to see if there are any fluke eggs in the pooled samples.

Monitoring Cows

 Don’t  forget the cows. Fluke is more of a chronic disease in cattle. Essentially they have larger livers and can cope with moderate numbers of fluke without too many problems. The disease will have an impact on the way they grow and milk so it is important to monitor the situation, especially if their fields are grazed be sheep in the winter. Again pooled faeces samples from up to ten animals can be checked. If you have a milking herd a bulk tank sample can reveal the likely presence of fluke in the herd. It is not easy to drench cattle for fluke, this applies particularly to milking cows because of the need to time the treatments for when the cows first go dry. We usually find it is better to check a sample first to determine whether or not treatment is necessary.

Barren Ewe Check

Intervet have announced that they are again running their barren ewe check for flocks with over one hundred breeding ewes. All you have to do is select six or eight barren ewes and we will come and take blood samples to determine their Toxoplasma titres. We can then see if there is active toxoplasma in the flock. Intervet will pay the laboratory charges as long as the blood is taken before the end of March. In the past some of the flock that we have investigated have not had to vaccinate against Toxoplasma.

Investigating Abortions

Sometimes we use blood samples to investigate ewes that have aborted. Really better samples are a foetus and some cleansing as a full range of test can be done if you can get them to the laboratory within twenty four hours of the pregnancy loss. This is not always possible when you are busy lambing, it is surprising how many abortions happen at week ends when the Veterinary Laboratories Agency is closed. By far the most common cause of abortion in ewes is Enzootic Abortion and/or Toxoplasma. It takes three to four weeks for signs of Toxoplasma to be revealed in blood samples, so it is better to wait a while before any samples are taken. It is important to know what is going on in your ewes. Infectious abortions often starts quietly, there might be just one or two abortions in the first year then many more in subsequent lambing seasons. It is possible to avoid abortion disasters as long as you monitor what is happening to the ewes that have not reared lambs for you this time.

First Feed

It is important for all young mammals to get an adequate quantity of colostrum within six hours of birth. Colostrum is rich in nutrients, such as protein and fat that promote growth and development. It's also the newborn lamb's only source of antibodies to provide immune protection, neutralizing bacteria and viruses to prevent infection. At birth, newborn lambs don't carry any protective antibodies, because antibodies do not generally cross the placenta from the mother to the fetus. Instead, the health, survival, and performance of newborn lambs is greatly dependent on the ingestion of colostrum.

Valuable Antibodies

Depending on their birth size, lambs require between 6-16 ounces of colostrum-10% of their weight in colostrum. The ability of the newborn lamb to absorb the antibodies in colostrum is at its peak within the first few hours of life and decreases over time. The value of getting even a few ounces of high-quality colostrum into the lamb within the first two hours after birth cannot be overemphasized

 Design Fault

The problems for ewes are that they only have two teats and it is difficult to be sure that all of the lambs have suckled if you are lucky enough to have triplets or more. Young lambs tend to suck on anything that will stay still for long enough. Often the first thing they suck  is wool. This may well be contaminated with E Coli unless you have very clean pens for the pregnant ewes.

Milking Ewes

Artificial colostrum is expensive and it does not have specific antibodies against the infections that you have on your farm. Fortunately the long chain proteins that are the antibody fraction in colostrum can be stored in a freezer with no loss of potency. If you can, at the start of lambing when things are quieter, take some time to milk colostrum from ewes that have singles or lots of milk. The oxytocin injection helps when you do this, but it is not essential. Divide the first milk into 10 ounce bags and store in a freezer for when you need it. It is not a good idea to use cow colostrum for lambs as it will not be digested adequately and will lead to anemia in the animals that have had it.

Older Cows

You will be aware that the Older Cow Disposal Scheme or cattle born before 1^st August 1996 has come to an end and that they no longer have any value. There are many older suckler cows that are still productive and the only option for their disposal now is as fallen stock. Cattle do not necessarily have to have died to be eligible for the fallen stock scheme. In many ways it would have been better to have continued the Older Cow Disposal Scheme until all of the animals had come to the end of their useful lives, but this is not going to happen now.

Back to Newsletters