BVD Key Points Pre-Mating

BVD and Breeding Bulls

With breeding bulls the most important things with BVD control is to ensure:

  1. Your bulls are not carriers of BVD. This carrier state is called persistently infected (P.I.). The antigen test for P.I. status is usually done by bull breeders prior to sale. If unsure get your bulls blood tested.

  2. The bulls do not get a transient infection (T.I.) of BVD during mating. If naïve bulls are introduced to a herd of cows with calves at food they can get the "flu-like” symptoms which effects semen production for up to 6 weeks. To prevent this situation you can:

    1. Ensure the cow herd with calves is clear of P.I.'s

    2. Vaccinate bulls with a BVD booster prior to mating.

What you can do with your bulls prior to joining:

  • Check their status with source to ensure they are blood test antigen negative.

  • Booster vaccinate if they have had vaccine prior or start with a 2 shot vaccine programme 4 weeks apart.

We do sell smaller vials of BVD vaccine for bull teams. If you were going to do one easy thing for BVD control it would be vaccinate service bulls each year.


Have they had exposure? To find out we run a pooled antibody test on 10-15 samples to check for herd exposure. This is a different test from the antigen test for P.I. status.

If yes and exposure is high - then vaccinate or eradicate prior to mating.

If no - focus on biosecurity, especially during 1-4 months pregnant state when exposure can result in P.I. formatting.

Lamb Rearing

The ad lib way - like what mother does.

We are excited to have in-stock the Heatwave automatic lamb feeders. There was a number of farmers last year that got these and it has changed the way they view rearing extra lambs. “Lambs do a lot better, and it is much less hassle”. It mimics what happens naturally. Lambs are never completely emptied out, so always have energy in the system to grow optimally. Because the stomach is full, they don’t gorge and blow-up like they can do on twice-daily feed milk replacer.

The Heatwave are a simple design and much lower cost than the bigger commercial scale feeders that are fully automated.

The work required is to mix cold milk once per day and clean the piping through with water and alkali (5 minutes and very easy). Training the lamb on the teat will depend on the lamb and the teat type. They still require colostrum for 3 days. This will not flow very well through automatic feeders.

Have lamb starter mix and fresh water available. Scratching pet lambs earlier is advised with automatic feeders to prevent them spreading scabby mouth.

What milk powder?

We have Sprayfo milk powder in stock. It prevents bloat deaths at that 3-6 week stage, especially with bottle fed lambs. It also works well in automatic lamb feeders due to its ease of mixing. Other standard lamb milk replacers can work in automatic feeders also.

Meal and quality grass

To make lamb rearing “stack-up” getting lambs onto meal/muesli seems to be critical. This develops the rumen environment faster. On a per kg of energy basic meal is 1/3rd the price of milk replacer.

If bottle feeding lambs when lambs are eating 100gm of meal per day you can drop out a milk feed (~400ml). The early milk wean system is when lambs are eating 200gm of meal per day then they can be weaned (10-12kg liveweight) and remain on 200-600gm of meal per day for another month whilst on grass until 25kg liveweight. The trick is to keep the hens, birds and adult sheep out of it!

Quality spring grass for orphan lambs will ensure best results.

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Clostridial Boosters Pre-Lamb

Which vaccine? We stock clostridial vaccine that has been rigorously tested, reliable and has good science and technical support behind it.

Multine 5 in 1 works. It has clostridium perfringens type D (plus tetanus and 3 others) that is the main cause of pulpy kidney. It has been shown to have higher antibody peak than other 5 in 1 vaccines. We take the view that more antibodies are better, and covers variables of lambing date from vaccination and amount of colostrum ingested by lambs. Multine 5 in 1 also comes with B12.

Covexin 10 in 1 is favoured when the clostridial risk is greater and for stud stock. The risk is higher for ewes and lambs when grazing legume dominant or high sugar feeds, for example Lucerne and fodder beet. Covexin 10 has been shown to have excellent antibody levels and superior to other 8 in 1 vaccines.

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Deer Scanning

Hind pregnancy testing is fast approaching. This is a perfect opportunity for deer farmers to have a comprehensive discussion with their vet around farm targets and potential animal health requirements for the up and coming season. The optimal time for hind pregnancy testing is 35-80 days after stag removal.

Production benefits of scanning:

  • Scanning allows for the culling of empty hinds to allow for better feed usage throughout the winter, for example more feed can be directed towards pregnant hinds. A hind can eat up to 200 kilograms of dry matter over a 90-day period.

  • Foetal aging can be used to identify hinds that have conceived in the first cycle. Early conception is a moderately heritable trait, which allows for greater selection pressure when marking replacements.

  • Identifying early calving hinds allows for preferential feeding based on likely fawning date. Well-fed hinds prior to fawning have been mammary development, and consequently increased milk production.

  • Early born fawns have greater weaning weights which is a desirable outcome as it correlates to greater lifetime production whether it be through higher velvet yields or increased slaughter weights.

Contact one of our vets today for an accurate and efficient scanning session.

New Research - Reducing Bearings with Vitamin ADE

A vaginal prolapse study involving around 2000 ewes in North Canterbury has shown some promising results. Half of the 2000 ewes were treated with Vitamin ADE at different stages.

The treated mixed age ewes had significantly less bearings compared with un-treated controls. In the two treated groups the risk of a bearings was reduced to 25% and 37% of that treated controls.

This is similar result to the LSD mineral drench trial that one of our Otago clients did. In this situation the bearing rate reduced by 2/3rds in LSD treated ewes.

Why would this mineral have an effect?

Bearings are very multi-factorial. They are a function of abdominal pressure and vaginal wall integrity. The changes in pressure comes from variation in rumen fill, abdominal fat, bladder fill, uterus size and development.

The smooth muscle function and tone is effected by calcium levels and previous trauma. Vitamin D increases the absorption of calcium from the diet and helps with bone and kidney mechanisms to do with calcium regulation. Some forms are derived from sunlight, other forms from certain feeds. Vitamin D is lowest in the winter when sunshine hours are lower. Mid-winter shearing has shown to reduce the risk of bearings in multiple bearing ewes. Is this because their skin is exposed to more sunlight and more Vitamin D? We assumed it had something to do with increased metabolism, burning abdominal fat and moving around more. Perhaps it is both. This is not going to be the total solution, but it is another piece to this complex puzzle.

Feeding Ewes Early Pregnancy - Setting up for winter

If ewes are in optimal condition, once passed the 1st cycle of mating, they do not need to continue to be gaining weight. But are they in optimal condition? With feed quality generally being poorer and less abundant this autumn, ewe condition may need attention sooner rather than later.

Body condition scoring and feed budgeting is the way to take the guess-work out of this subject. I expect more ewes may not have achieved optimum BCS 3 this mating and it will be interesting to see how this effects ovulation rates this year.

If there are lighter BCS ewes then taking them out early makes it possible to “re-build” condition from now to the point of lambing. Adding BCS to light twin ewes after scanning and shearing is hard to do with the bigger foetus taking a greater part of reserves.

There is a need for astute feed planning this year. This comes in many forums. From measuring pasture cover and grass growth rates to measuring crops and testing the dry matter and energy content of baleage. The Veterinary Centre can assist with this process. Just bring in a recyclable bag full of feed to test.

Ryegrass Staggers

Over the last couple of weeks we have diagnosed cases of Ryegrass Staggers in both cattle and sheep in the Haka Valley. Outbreaks of ryegrass staggers occur mainly in summer and autumn in sheep grazing perennial ryegrass containing the fungus Neotyphodium lolii. This fungus produces toxins which in turn affect neurological function and the following clinical signs may be seen:

  • Trembling of the head and twitching of muscles over the neck and flank

  • Head nodding

  • Erratic limb movements

  • Balance issues (hence “staggers”)

  • Eventual collapse with worsening symptoms - with head extension and rigid legs

Clinical signs arise roughly 7-10 days after ingestion of toxins. While direct death from ryegrass staggers is rare, losses arise from sheep with clinical signs being caught in ditches or fences.

A quick fix to ryegrass staggers is not available and treatment recommendations involve moving to safer pasture or feeding out an alternative feed source and ensuring the affected sheep are in paddocks with few hazards. Mycotoxin binders are often marketed to help, but little scientific data proves their efficacy.

Long term strategies to control ryegrass staggers are often expensive but are effective. These include:

  • Avoid grazing of ryegrass during risk periods (late summer/autumn)

  • Grow rape or other fodder for late summer grazing

  • Develop lucerne paddock

  • Feed silage

Management Crucial to Parasite Control in Deer

Your management is crucial to parasite control and the amount you have to rely on drench. You need to get into the mind set of constantly evaluating the level of parasite challenge you are exposing your weaners to.

  • Ingestion of infective parasites is higher the lower you force weaners to graze

  • Areas of the farm that are constantly used for weaner grazing will build up higher levels of infective worms

  • Utilise new pastures for weaners and “cleaner” pastures e.g. post-baleage/silage harvest

  • Weaners that are post-rut weaned tend to need less drenching through autumn

  • Use other livestock to “clean up” pastures behind weaners. Integrated farming will play a huge part in sustainable parasite control in future

  • When to start drenching weaners and how often is entirely dependent on the level of parasite challenge on an individual farm. We do know that infective lungworm and gut worms will be on many deer farms in January and animal health issues can arise which necessitate that first drench being given in late January/early February. This is particularly so on the more intensive deer farming operations.

    Local deer farmers who have had a drenching programme developed by the Veterinary Centre are now getting their animals away earlier at heavier weights.

Feet Soundness

Now is the time to sort out feet post weaning. It has dried out so spreading of footrot should have slowed down. Making a good job of inspecting all feet is important. Drafting off limping sheep is not very effective at removing infection from the mob. Antibiotic treatment of lame sheep seems most effective when the affected foot is deprived of moisture, and we have had some very good reports post treatment with tilmicosin (Micotil/Tilmovet). If there are still some signs of scald and early footrot in your flock then trough 2-3 times, 1 week apart to help break the cycle before rolling over and making a clean mob.

To keep the clean mob clean check again in 1 month. Catch anything limping or suspicious.

Treat infected animals with long acting tilmicosin (vet only administered). Re-check for cure in 14 days. Lincospecin and oxytetracycline are still available and can be administered by the farmer but to get really good cure rates grating in the woolshed for 24 hours post treatment is required.

We are planning on having some footrot workshops in March so let me know if you and your staff are interested in attending.

What comes with a Green Summer?

Worm control: with the extended, wetter than normal summer worm control is very important. Missing a drench or extending intervals could lead to rapid build-up and contamination of pastures.

Wormwise - Seasonal Update: many of you have attended our Road Show events or read about sustainable worm control message. I thought for each seasonal period I would break down some of the key messages.

Lambs post weaning:

  • Use an effective combination drench. A triple combination or novel is best.

  • Stick to a 28-30 day drench interval.

  • If you really think there has not been any significant worm challenge then monitor with faecal egg count to ensure your assumption is correct.

Pre-tup drenching of ewes:

  • Use the most effective drench.

  • Utilise some refugia - that is leave some undrenched. Tag/mark them to monitor.

That’s not too complicated? It is a worthwhile exercise to review your Animal Health habits and rationale with us….

How do I get a Reduction Test done? Easy

  • Tell us when you’ve got lambs in the yards for weaning.

  • Set aside 80-100 that don’t get drenched.

  • Get 10 faecal samples for an egg count to ensure enough worms are present.

  • Then we do the first visit when you are ready. (The first visit takes about an hour.)

  • A week later we return to collect the 2nd dung samples to see if any worms remain after the drench treatments.

  • We analyse the results and send a comprehensive report of the drench resistance status of your farm.


Effective Flystrike Prevention Following a Wet Spring

Fly strike in sheep is one of those things that is best to put the effort into prevention. Coming back from Christmas holidays to find fly blown lambs and ewes is very demoralising. Even a 50c piece size area of fly strike can stop a ewe cycling for a month. For lambs the loss of growth, suffering and deaths, along with the time dealing with the mess, are enough for many to vow to get things sorted before Christmas next year….

The obvious measures are to ensure stock are clean and don’t get wormy. So crutching and a regular effective drenching program are essential pillars to preventing fly.

There are generally 3 waves of fly pressure, the first few appearing around December, then the second and bigger wave in mid-summer and the third wave mid-autumn. This is important when planning your program especially in relation to persistent activity and application time.

Your fly-lice program for your sheep flock can be complex with the range of chemicals now available. There is a general move towards being more aware of chemical resistance and using these resources in a planned and sustainable way.

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Animal Health in a Growthy Spring

It is a great opportunity with the current conditions to feed animals optimally, establish winter feed crops and recharge supplement supplies. However, many farmers comment that stock don’t “do” in lush, growth conditions.

November Animal Health to consider taking action on:

  • Docking drench of ewes, especially if they have not had long acting treatments pre-lamb. We have had reports of ewes responding well to this. You can do a FEC (drench check) to work out if a docking drench is required, or just target lights and 2 tooths.

  • Pre-wearning tape drench of lambs. Tape drenches can provide an extra kilogram of liveweight gain if given one month prior to weaning compared with standard drenches.

  • A combination drench for yearling cattle, plus B12 and selenium if not previously addressed.

  • Fly was a big headache last year for many farmers. Clik spray-on is widely used in fine wool at tailing. It is in short supply this year, so ring Jeff to secure your order. Vetrazin spray-on, or Clik-zin spray-on is suitable for cross-breds.

  • If lice was an issue over the winter use a diflubenzuron jetting fluid (Zenith or Fleecemaster) for your fly-lice treatment. Use Cyrex if strike is present. For a pour-on option Encore will have good lice knock-down with reasonable fly protection - just be aware of the longer meat withhold period.

  • Feet are going to be a niggle this spring and summer, if preventative measures are not undertaken prior to Christmas. Treating lambs at tailing for lameness can be well worth it. Having an extra person squirting blue spray between scaldy toes works really well to break the cycle and keep their growth rate on track. Foot bathing cycles are also warranted post tailing.

B12 at tailing is there a benefit to supplementing lambs?

If ewes have not had a bionic capsule or boost of B12 pre-lambing there is a possibility that lambs could end up with depleted B12 levels by weaning time. We don’t routinely test for B12 levels in pre-weaned lambs, but I have found some ewes with marginal to deficient levels of B12 at pre-lamb. It therefore may be of benefit to top-up B12 levels at tailing in lambs before they become deficient.

A 0.5ml dose of smart shot can elevate B12 levels for ~3 months. Smart shot users seem to keep coming back to it and it is the only serious way to correct low B12/cobalt issues. Short acting B12 can be useful for maximizing weaning drafts if B12 levels are low.

Scabby Mouth

As tailing approaches so does the most practical opportunity to vaccinate against scabby mouth.  This is not new but it is timely to go over the basics to ensure your procedures are giving you an effective vaccination programme.

  • Scabby mouth infects animals through breaks in the skin resulting in raised red lesions and scabs.  Infections can occur anywhere on the body with the mouth, feet, udders and the poll of rams being very common.  Lamb infection results in significant effects on weight gains.
  • Lambs are most susceptible over their first summer so tailing is the most practical time to vaccinate.  Don't use the vaccine on farms that are free of the disease.
  • The best place to give the vaccination is the inside of the back leg unless fly treatments are being used, in which case the inside of the front leg should be used.
  • The vaccine is given by scratching the skin but don't scratch so firmly as to draw blood.  A blue dye is added to the vaccine so you can see where it has been applied.
  • Check the vaccination area of 20 lambs 7-10 days after vaccination to ensure that it has taken.  A take is a raised whitish line surrounded by an area of inflammation.
  • Keep the vaccine in a fridge until it is used and only take enough for the day.  During use keep it in a chilly bag and out of direct sunlight.
  • As scabby mouth can infect humans (orf) don't touch lesions or prick yourself with the vaccine.
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Options for the Successful Treatment of Bearings

Bearings are a function of internal pressure and vaginal wall integrity.  The internal pressure changes come from:

  • Rumen
  • Bladder
  • Uterus
  • Abdominal fat
  • Gravity

That's why triplets have the greatest risk (more uterus volume).  That's why gorge feeding, feed changes and bulky feed can be a risk: the rumen expands rapidly and produces more gas when not adjusted.  That's why sitting down for long periods, and high water content feed (fodderbeet and swedes) and salt can be a risk: the bladder gets bigger.  That's why weight gain post mating is a risk: increase in abdominal fat.  That's why low calcium levels are a risk: smooth muscle not as toned (and why Vitamin D might help).

For these reasons that why exercise throughout the day, consistent rumen fill and feeding levels are protective against bearings.  However we can't prevent them all.  Successful treatment of bearings relies on early detection, expression of the bladder, gentle and clean replacement and effective retention.  Exposure time is a prognostic indicator of success.  Early treatment involves thoroughly cleaning the vagina and gently lifting it to allow the ewe to urinate.  Following prolapse, ewes are unable to urinate due to a kink in the urethra.  Lubricant should always be used and gentle even pressure applied to replace the prolapse.  Replacing the bearing is easiest when the back end of the ewe is elevated.  Retention of the bearing can be by external pressure from a number of options including internal bearing retainers, harnesses or a purse string suture around the vulva with umbilical tape or suture.  All ewes should be prophylactically covered with antibiotics.  Suitable choices are a Penicillin of Tetracycline derivative.

Pre Lamb Drenching

Pre-lamb drench topic is a hardy annual topic for vet-farm discussions.  The fact is parasitism is always going to be a cost to production and as seasons and farm systems change, our approaches to worm control need to adapt.  I have been busy these last few days discussing pre-lamb animal health with farmers.  It is a process that I think is valued by those that want to rationalise their decisions each year.

I do encourage farmers to consider all the tools available and take on board the sustainable drench use message.

A key 1st principle message is to reduce larval challenge in young stock, and optimise breeding stock condition and feeding during lactation.  Farms that achieve this are not only going to beat the worms, they are going to be vastly more profitable.  The application is the complex bit......

To Do:

  • Get a plan for worm control this spring
  • Think what is best for my capital stock in the current conditions
  • Work some refugia into your plan.

Feeding Ewes Early Pregnancy

If ewes are in optimal condition, once passed the 1st cycle of mating, they do not need to continue to be gaining weight.  The excess of grass around this year means it will take proactive management not to allow breeding ewes to gain weight in the 1st trimester.  May to June is an opportune time to tidy up poorer quality paddocks or even feed-out 2nd year baleage to conserve green feed for later pregnancy.

I do not like to discourage farmers from feeding stock well, but there is some evidence showing that there is an increased bearing risk with weight gain through this period.  Yes lamb birth weight is affected by feeding levels at every stage of gestation, so it makes sense to save better quality and quantity of feed for twin bearing ewes after scanning.

Body Condition Scoring

BCS and feed budgeting is the way to take the guess-work out of this subject.  I expect more ewes should be in better than BCS 3 this mating and will be scanning well this year.  The next bit is to set them up for optimising lamb birth weight and survival without getting them stuck upside down cast or poking their back-end's out.

If there are lighter BCS ewes, then taking them out early for preferential treatment makes it possible to "re-build" condition from now to the point of lambing.  Adding BCS to light twinning ewes after scanning and shearing is hard to do with the bigger foetus taking a greater part of reserves.

Ewes Hoggets

The recommendation is slightly different for ewe hoggets.  These need to keep gaining body weight through mating and early pregnancy, ideally 4kg per month from now to the end of June should see a standard cross-bred hogget reach ~50kg.

Nitrate Poisoning

It is again the time of year when Nitrate Poisoning rears its ugly head.  With the widespread excellent autumn growth conditions, many farmers are taking advantage of applying nitrogen to boost growth leading into winter.  One thing we do know is that when plant growth is slowed by cold or overcast weather, plants will accumulate nitrate.  The first sign often seen in livestock is sudden death so plant testing is essential before placing stock on any at risk crop or pasture.  Drop samples into any of our clinics or arrange for our Territory Managers to come and sample.  We can test within the hour at all of our clinics or if large numbers of samples are required to be tested we can provide a kit and training on how to undertake samples yourself.

Free BVD Screening with Beef Pregnancy Testing

In previous seasons the Veterinary Centre has been able to secure funding to cover the lab fee component of BVD screening of beef cattle herds.  This year this initiative has been extended so that during pregnancy testing visits our vets are now able to take a set of samples from the herd and have them screened for BVD at no charge to the farmer.  This gives our practice the unique opportunity of effectively mapping our entire district for prevalence of BVD in practically all the beef herds in our district.  This information will be invaluable in guiding our veterinarians and farms in the make up of BVD control plans.  If you have any questions just talk to one of our beef pregnancy testing team.  There is nothing required from the farmer except to give permission to take the samples, our team will take care of the entire process and provide you with the results for your herd.