Changes after Calving

After parturition the uterus of a cow or ewe has to go through a number of changes if the animal is going to be able to breed again. At the time of calving the uterus of the average cow has a weight of 13 kg, this is expected to reduce to just 1kg after three weeks. It is a dramatic change, over half of the weight is lost as the caruncles which attach onto the placenta of the calf are shed and pass out with the mucus. Most animals will have a bacterial infection in this discharge, but it is only a minority that go on to develop metritis that will need treatment. Cows that have twins or hold onto the placenta for more than twenty four hours are more likely to develop metritis that will need treatment. Any cow with a red brown watery to a white blood stained purulent discharge more than three weeks after calving will need help to clear up the infection. On some farms the mucus from all of the cows is examined ten days after calving, if there is more mucus than debris no action is needed. Mucus samples can be taken fairly easily if you introduce a gloved hand into the vagina. If there are definite signs of infection a three day course of a no milk withhold antibiotic or a single prostaglandin injection may be needed. It is important to resolve the infection at this stage as it will respond better to treatments now before it becomes fully established.

Acorn Poisoning

There seems to be a good crop of acorns this year so we need to be careful to prevent any possible poisoning by  acorns and oak leaves. Acorns contain gallotannin which in the rumen is broken down to gallic and tannic acid. It is the tannic acid that will cause ulceration in the mouth, gullet and throughout the intestines. Tannic acid will also lead to renal failure. It is this that is the main concern as many cattle that survive acorn poisoning will be severely compromised and often struggle to maintain their weight and produce little milk. Pregnant cows can give birth to deformed calves if they go near the trees in the early stages of pregnancy. Birth anomalies are usually blamed on the Schmellenberg virus now a days but there are other causes as well.

Prevention

Acorns are bitter so given the choice most cattle will avoid them unless they are have found their way into water tanks or feed troughs. Some animals seem to enjoy the taste of acorns and will search them out and are at risk from the accumulated affects of the poison over a number of years. If you have several animals that may have eaten acorns hydrated lime fed at 1kg per animal each day can significantly reduce the effects of the poisoning, but by far the best way of stopping cattle getting poisoned by acorns is to deny them access by fencing off oak trees and making sure the leaves do not end up in water troughs. Spreading slurry under the trees does seem to help as long as you repeat it to make sure all of the acorns are covered when they fall.

Schmallenberg Virus

Thinking of deformed calves there haven’t been any reports locally in the past two months as far as I can determine. Really this is the time of the year when it should be quiet as calves born now were served in the middle of the winter when there were no chances for the virus to circulate. There is little information about the Schmallenberg virus on the DEFRA web site as the relevant pages do not seem to have been updated this year. Some thirty blood samples have shown the presence of the virus in Scotland, but even this does not seem to be a significant number as many regions reported only one or two animals that had been exposed to the infection. The vaccine is still available but the restriction on not being able to give it to pregnant animals, double dose for cattle and the price seem to have limited its use.

Advertisement Ban

I cannot understand why the Veterinary Medicines Directorate has banned the advertising of prescription only products to you farmers. Veterinary Surgeons and Veterinary Nurses are sent different magazines each week either at no cost or at a considerably reduced cost because of the advertisments from the drug companies. Some of the articles in these publications tell you things you already know, but you can always find something new or something of interest from the letters that others have sent in. I don’t consciously look at the adverts as there are only a limited number of different drugs available to us and many are generic copies of those that we already have. I also get complimentary copies of some of the publications that come through your door and again I can find things of interest but now the new regulations are that you are not to see any material from drugs companies that may influence your purchasing decisions.

Existing Controls

There have always been restrictions on how prescription only medicines can be advertised companies are not allowed to make claims that they cannot substantiate and they are restriction on promotions stating that farmers who brought this one product also brought something else. I should imagine that this will cause all sorts of problems as the drugs companies often contribute a substantial part of the advertising revenue and it may be difficult for some publications to continue in their present form.

Promotions on Web Sites

No doubt the VMD will monitor adverts for antibiotics and prosecute those that break the rules. To find out more about this I typed a few words into my computer and looked on the internet. Type in the name of an antibiotic and you will get pages and pages of promotions and what to buy as well as that particular antibiotic or vaccine. I would be very surprised if all of these are going to disappear when the new regulations come into force.

Allergic Reactions in Suckler Cows

Every year at about this time I mention Fog Fever as it will affect somebody again this autumn. It is a condition that does not always respond to treatments unless it is noticed early. You will remember that Hereford and Hereford cross cows are particularly at risk. It occurs soon after cattle have moved onto better grazing. Generally it happens to cattle that are not having supplementary feeding and animals heavy in calf seem to be particularly at risk. Now you know the risks, try not to move vulnerable animals onto fields with lots of grass, let young stock or sheep onto the pasture first. After any pasture change at this time of the year try to see all of the cattle at least twice each day and get them to get up and move as Fog Fever can be difficult to detect in the early stages. It may be too far advanced to treat if you miss the first signs. Over the years we have found that intravenous steroids are the best treatments for this condition. This may well contribute to the loss of a pregnancy, but does help to the prevent the loss of a cow.

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