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Posted: Fri Dec 28, 2007 6:06 pm
by rodmet
Once again the beef finishers around here are having a terrible job with pneumonia in their cattle, including a friend of mine who has regular problems and although this year he has fed a special and costly additive recommended by the vet he lost 5 beast recently,
Touching wood, I have never had a single case nor heard of one among Dexter keepers and I wondered if that was most people's experience.
If pneumonia is as I suspect very low in Dexters why is this? and is it another unique selling point?
Posted: Fri Dec 28, 2007 7:19 pm
by Duncan MacIntyre
Calf pneumonia in Dexters does not often seem to be a topic of conversation, and there may be several reasons for this. Many herds are small numbers, low density, usually reared as suckled calves, and many are finished on farm of origin rather than shifted through markets to finishers. There are more large herds of Dexters now than there ever have been, it will be interesting to hear from owners of large herds if they see much. In Scotland calf pneumonia tends to be most problem in dairy calves from 4 weeks to 4 months, and in beef suckled calves after they are sold off the mothers, often travelling considerable distances, and most significantly groups from different herds are mixed.
However maybe there is something about the breed making them less susceptible, just as there is recognised increased susceptibility in a certain well known double muscled breed.
Duncan
Posted: Fri Dec 28, 2007 8:47 pm
by welshdexterboy
I think the answer is the low density of numbers for that time when they come in to sheds for the winter. Many of us have low numbers and in most cases of pneumonia it is in sheds with poor ventilation, mild weather, high stocking rates and poor stockmanship. An old farmer I knew many years ago would put any calves showing signs of P outside. They would be free from draft but plenty of air movement. I dont think it could be used as a selling point.
Posted: Sat Dec 29, 2007 8:39 am
by Rutherford
Unfortunately my experience has not been that of other contributors. My calves suffer every year, whether they are in buildings or totally outside. When I put my building up I was assured my calves would be safe, but it hasn’t provided immunity. I don’t think you will find my Dexters more vulnerable than many from what I have heard.
My vet tells me he does not know of any cattle in this area that don’t contract it. This is a wet farm and down in a hollow, not good rearing country, although undoubtedly bad housing or poor stockmanship can encourage it. For years my vet put me off using a vaccine, but has recently suggested one of the newer ones might be appropriate.
Posted: Sat Dec 29, 2007 9:48 am
by Sylvia
I wonder if anyone who has not suffered from this and has a large herd would tempt fate by saying so, not me, that's for sure.
Posted: Sat Dec 29, 2007 10:18 pm
by welshdexterboy
Question for Duncan really-- If Rutherford's cows and calves are getting it so regularly why do they not build up resistance? Is it because it is a virus or is it like the common cold and there are too many varieties? I know it is coming up to Hogmany so in your own time. Happy New Year to you Sir.:D
Posted: Sat Dec 29, 2007 11:33 pm
by Duncan MacIntyre
Always tricky to comment on specific situations, and I certainly would not want to tread on toes of Beryl's vet, who will know a lot more of how her cattle have been affected than I do. I certainly do know the general situation of the farm, and would agree fully with Beryl that it is very much in the bottom of a hollow, heavy land with a tendency to be wet. I would imagine that either in sheds or out in the open there will be periods of high humidity and still air, which will make the spread of airborne infection much easier. I can't quote exact figures but the relative humidity makes a HUGE difference to the spread of organisms between animals. Calf pneumonia is caused by a large number of viruses and bacteria, and maternal anitibodies may protect the very young calf but this will get less as they get older. So as the calves grow they will be susceptible to infections which the previous years calves will have encountered and become immune to, and may have suffered pneumonia in the process. If there is a wide range of organisms involved on the same farm, and if the age at which the calves become affected covers a wide range, it may well be difficult to devise an effective vaccination programme. Some modern vaccines cover a wide range and seem quite effective, eg Rispoval-4, or some which include Pasteurella, one of the commonest bacteria involved. But if the calves are being struck down quite young it may be difficult to have time to get the right number of doses in before the disease shows, and if they are very young three doses are needed to ensure lasting immunity, making the exercise more expensive. With sucker herds there is the added problem of handling the cattle, whereas dairy calves being pen reared are easily on hand at the right time. When calves are running outside there is also the possibility of infection from neighbours, either by direct contact accross fences or by spread in the air. On Bute I sometimes see outbreaks of pneumonia in suckled calves which are outside but do not have any direct contact, so I am tempted to blame spread in the wind. IBR of course infects animals for life, so if it is present in a herd (and I do not mean to suggest that it is in Beryl's case) evey infected animal remains a carrier just as we do after chicken pox. This means that an apparently healthy animal can start shedding virus at times of stress so there can be a reservoir within the herd. BVD by itself can cause pneumonia but can also depress the immune system so calves with active BVD infection, and for a spell after, can be more susceptible to other bugs.
Duncan
Posted: Sun Dec 30, 2007 6:27 am
by Broomcroft
We have two large, double-story agricultural buildings. Built in the 60's, the idea being to keep livestock below and straw/forage above. They became known as pneumonia barns with fully grown cattle dying regularly. We now use them without a problem by leaving the upstairs empty so there is a good air-flow and no dust.
But there is one area that is lower, damper and slightly more enclosed than the others and if we keep calves in there, they can get respiratory problems. You can feel the difference in the air quality in the problem area. Slightly damp and still as opposed to fresh, clean and dry.
Edited By Broomcroft on 1198992531
Posted: Sun Dec 30, 2007 11:22 am
by Inger
Would large, slow turning ceiling fans solve the problem of stagnant air remaining over head? Rain proof vents at each end of the building should help as well, shouldn't they?
Posted: Sun Dec 30, 2007 11:55 am
by Broomcroft
I'm probably going to raise the floor because I think the basic problem is actually dampness caused by it being just a bit lower (about 700mm) so water gets in and doesn't clear as quickly.
Posted: Sun Dec 30, 2007 2:00 pm
by Rutherford
The Woodmagic herd has been ‘IBR free’ for many years, more recently I have vaccinated against BVD. The calves usually go down with pneumonia when the effects of the colostrum immunity are beginning to wear off. . I suspect it drifts down from my neighbours around.
My building was designed to put accent on ventilation. I was anxious not to provide a climate that would give the cattle a check when they went out to graze in the spring.
My vet advised against vaccination before there were the more targeted drugs for the various strains. We recently took blood samples, and it is on the strength of those he has recommended one that may help, but it is a bit of a performance when their age is not constant, and they have to be treated twice