Too much concentrates at this late stage in pregnancy may cause fat lay-down, especially in the pelvic canal. Heifers of pedigree beef breeds are quite vulnerable when it comes to calving if fat is lining the pelvis. The tissues are softer and more likely to tear if a layer of fat is just below the surface.
As the heifer tries to force the calf through the narrow pelvis, the fat gets pushed along under the thin tissue lining of the birth canal. This fat blob is eventually forced out through a tear and the heifer is left with lacerations of her canal. This painful infected area we see several days later makes for a difficult time for the mother with her newborn calf.
Excess feeding late in pregnancy was also said to cause the birth of an over-sized calf. This is not entirely true as the calf's genetics are the main factor in the birth size. Even a thin cow can give birth to a large calf. The myth of starving a cow late in pregnancy to make for a smaller calf does not hold water.
In the absence of concentrates we must keep a close eye on mineral intake. Each area in the country will have different mineral requirements, depending on soil type and on the source of hay or silage. No single rule works for all, but certain minerals require attention on all farms. Magnesium and calcium are top of the list. We need high magnesium but low calcium inclusion on most farms.
The cow needs calcium to help form the developing bones of the unborn calf. She also needs calcium just at calving time as she turns on the big switch to milk production. However, we must not give a high calcium mineral mix pre-calving as the cow becomes dependent on that source for her everyday requirements. This source is never enough immediately after calving and the cow must quickly turn to her own bone marrow to mobilise some in a hurry.
By feeding a lower calcium level before calving, she will have opened up the pathways of calcium from the bones and thus avoid the sudden shortage just after calving.
To put it plainly, this avoids milk fever. And so a dry cow mineral mix should have lower calcium. On the other hand, we need plenty of magnesium throughout the time from late pregnancy to early lactation. We also need it when grazing the new spring grass in late March and early April to avoid tetany.
Selenium is low generally in this country but beware of selenium-toxic soils in some parts. Areas along the eastern seaboard are high in selenium and so we should not include it in our dry-cow mix. Local knowledge is vital here, so ask your vet.
Adding a mineral to an already high level can cause endless problems with dead calves, retained afterbirths and ill-thriving adult cows. Be careful as you pick your mineral mix.
Iodine is often low and this causes the birth of weak or dead calves. What a waste it is to see dead calves in the calving pen. Iodine top-up is a daily requirement and needs constant monitoring.
Copper is low as a general rule as it is bound in the soil by other elements. Copper inclusion in mineral mixes is required on most beef farms.
Preparing the Beef Cow
Now is the time to check that all the vaccines are done and covered before the birth of the calf. With correct vaccination protocols we should have the colostrum primed to allow full protection be passed from dam to offspring via the first suck. Each farm will have its own vaccination protocol. This should best be laid out between the farm vet and the farmer in the form of a Herd Health Plan.
Salmonella vaccination is well advised, especially when calving indoors. A salmonella outbreak will cause severe scour with all too many fatalities among the young calves. Treatment is very time consuming and expensive, and sometimes to no avail. The disease is a zoonosis, meaning it can spread to ourselves.
If you have had salmonella on the farm in the past, then you'll understand very well why we say we should vaccinate against this. If you haven't seen it before on the farm, then ensure you never do, and consult your vet as to whether you should vaccinate or not.
E Coli is very similar to salmonella, and again, we should strongly consider a vaccination for the pregnant beef cow to give the newborn calf adequate protection. Disinfection and good husbandry helps to keep these bacteria at bay.
BVD, Leptospirosis and IBR should all have been considered long before this late stage of pregnancy. These vaccines are used at the beginning of the breeding season before the bull is introduced. Leptospirosis is found everywhere in the environment; in ditches, drains and stagnant water. The spirochete bacteria are spread by rats, dogs and other cattle, and will cause abortion if they strike during pregnancy. Since the disease can come into the farm from anywhere through ditches, hedges or gateways, it is best to vaccinate rather than stop it entering by restricting cattle movement. An annual booster is required to maintain immunity and this is best given before pregnancy.
BVD is a virus that can also cause abortion. However, this guy will cause many other problems because it attacks the cow's ability to protect itself from other diseases. In other words, it suppresses the immune system.
Therefore, BVD in a beef suckler herd will allow a whole range of diseases to get a foothold in the calves, as well as the adult breeding stock. A very high proportion of the national herd has BVD virus, and Animal Health Ireland (the new body involving farm organisations, Veterinary Ireland and Teagasc, among others) has put together a protocol to reduce the incidence of this disease in Ireland.
The reason we promote the use of BVD vaccine before pregnancy is because this virus can cross the placenta and cause the birth of a lifelong infected animal. This animal continues to shed the virus, keeping it alive on the farm, causing lifelong problems amongst other cattle.
Control of this disease involves identifying this persistently infected animal via blood samples and taking her out of the herd. Therefore, we see how BVD may come into your herd by the purchase of a persistently infected replacement heifer from another farm. Your farm vet will advise you how to protect your farm from this disease, but one important point is not to buy in replacement heifers during pregnancy. She could be a Trojan horse bringing in disease as your beef cows are at their most vulnerable with their developing foetii in the womb.
Worse again, the incoming heifer may produce one of these persistently infected calves onto your farm when she calves down, and spreads virus amongst all your stock during the lifetime of the calf. Rid your own farm of the disease and only buy in stock when the suckler cows are in the pre-breeding phase. Isolate and test incoming stock and your vet will advise how to proceed from there.
IBR has caused a real stir in the past few days with the news that the top bulls at the National AI Test Station had to be destroyed because of an outbreak.
This disease can spread from bull to inseminated heifer and so all the collected semen from that group of bulls since their last negative test had to be destroyed. The virus causes abortion as well as virus pneumonia and can hide in a herd in one or two animals for a long time.
Again, your Herd Health Plan with your vet will outline how your farm sets about controlling it by vaccination and by searching for any of these carriers. Other countries have put IBR control programmes in place and slowly, farmers and vets are putting control programmes in place at individual farm level here in Ireland.
Animal Health Ireland is the overall body that offers the framework to allow a national control programme and the sooner we buy into that, the better for Irish livestock.
Again, avoid buying replacement heifers during pregnancy as an incoming IBR problem at that stage will cause very big losses. Replacement heifers should come in when the cows are empty.
Parasites in the Suckler Herd
I've often heard of farmers giving a worm dose before turn-out as it's convenient when all the cattle are together. Worms are a grassland disease and are active only during the grazing season.
To say we need a worm dose in early spring is saying we've been feeding those unwanted parasites in the cattle's intestines all winter. What a waste! Control worms during grazing and ensure the last of the worm burden is treated at the beginning of winter. The first worm dose is not required until six weeks after turn-out.
Fluke is different to worms as some adult fluke could survive the autumn doses and still be active in cattle this spring. If this is so, then a fluke dose before going out to grass would be useful, as this helps to reduce the spreading of fluke eggs onto the spring pasture. Each farm is different, and, depending on fluke treatment protocols and the level of fluke burden, you may be well advised to treat now before those remaining eggs contaminate the newly growing pasture.
Some representative dung samples from a few cows can be tested by your vet for evidence of the parasite. This will form part of your overall fluke control. Remember, resistance to existing fluke treatments is on the increase, so a well-informed fluke dose regime is required by all stock owners in this country.
The dairy herds have their own difficulties with fluke doses, because of milk withdrawal times, but that is not the case thankfully in the beef/suckler herd. Lice, ticks and mites are the skin parasites and they can multiply to a great degree during the winter. The warm, thick coat of winter, coupled with close contact of the cattle indoors, gives a perfect environment for the spread of skin parasites.
This time of year is a good time to treat for them as lice infestation can be very debilitating on the pregnant cow.
If you don't need to treat for worms at this stage, then use a lice-only product and not a worm and lice combination.
Welfare is a big issue going forward in agriculture and livestock production. The consumer is increasingly asking about welfare issues in animal production systems. Thankfully, Ireland has extensive beef producing farms as opposed to the intensive farms of other countries. We can use this as a strong selling point for exports. But at home we must not take our eye off the ball.
Lameness, thin cows, poor shelter and bad underfoot conditions are all welfare issues. We must ensure that we improve in all these areas to maintain our top-class welfare status.
Peadar O'Scanaill is a vet in Ashbourne, Co Meath and is a member of the Animal Health Committee of veterinary Ireland