|
|
|
April 2004 Newsletter |
||
|
Things are changing This is the time of the year
when we take the majority of our Huskvac orders. It
used to be the case that the vaccine took a week or ten days to come and had
a shelf life of only two weeks. All of that has changed now. We order the
vaccine by fax and the boxes will often be delivered the next working day or
the day after that. Also they have managed to extend the shelf life of the
vaccine, as long as it stores properly. The vaccine that we are getting at
the moment has a shelf life of two months provided it is kept under
refrigeration. Lungworm is such a common disease in adult cattle now that
there is some advantage in vaccinating dairy animals that you intend to sell
so that they will not succumb to the infection in their new herds. Intervet has extended the vaccine season so that the last
batch will be available well into August with the second dose sent out in September.
This is to allow for the prophylactic treatment of cattle in contact with
clinical cases during the summer. Scouring Lambs Last year a large number of
lambs were lost in our area as a result of Nematodirus battus infestation in May and June.
This is an intestinal parasite that has a cunning twist to its life cycle.
Eggs from last years lambs are held in check for twelve months on the
pasture, after a period of cold weather, when the average temperatures get
above 10 degrees centigrade they hatch in vast numbers to overwhelm the
immune system of the young lambs. Animals from one month to three months of
age are most at risk, older lambs and adult sheep develop immunity to the
infection. Nematodirus develops quickly in the
lambs. It responds to all of the worm drenches as there have not been any
reported cases of resistance developing, but you might need to repeat the
treatments every three weeks on heavily contaminated pastures. The injectable anthelminctics are
not so good against this parasite. One of the reasons that it is able to get
established so quickly is that the infective larval stage develops inside the
egg and is thus able to establish itself rapidly in the intestine of the
growing lamb. Nematodirus battus can
be avoided if you can turn your young lambs out onto fields that were not grazed
by lambs last year. This is usually quite difficult to arrange so you will
find that you might need to drench them two or three times in the first part
of the summer. No more free Ear Tags Ketchums have announced that they have obtained British Standards
Approval for their Star and Half Star Cattle Ear Tags and that they will no
longer supply replacement tags free of charge. I am not quite sure exactly
what the connection is between the two statements or whether it implies that
now they are approved it is not their fault that the tags come out. That is
what they have said anyway. Abortion Storm Last month saw the return of Brucellosis to On Farm Slaughter The casualty slaughter reference
numbers that we have to get before animals can go for on farm slaughter have
been getting bigger and bigger. Today we were given a number just four short
of a million. The future of the scheme is still in the balance. When over
thirty month cattle are allowed back into the food chain downer cows and
chronically lame animals may be stranded, as it is most unlikely that any abattoir
will accept them for human consumption once they have been slaughtered on the
farm. The problems of getting them to the abattoir promptly without large
portions of the carcass being condemned for bruising or other damage means
that most of these animals will have no value. The current system works well
most of the time and something needs to be done to ensure that it can
continue. Making your farm Secure There is
all sorts of advice about biosecurity and how to
keep diseases out of your flock or herd. No doubt somebody will point out
that the mini Brucellosis breakdown could have been
avoided if the farm concerned had better biosecurity.
If only things were that simple. Whichever way you manage your herd you will
have to buy in some new blood from time to time. There are not many systems
where there is the opportunity to isolate incoming stock for three weeks, or
to take blood samples and do other tests before the animals join the main
herd. It is all too evident that even with the best scrutiny there are still
some things that can creep in. Severe Scour Recently we investigated an
outbreak of severe scouring in calves born on a dairy farm. This is not a
farm that ever has much of a problem rearing calves, but for some reason they
were getting young calves with a severe scour. Investigations revealed that
it was a combined Rotavirus and |
||