Sudden Death

Recently we have had some post mortem investigations of sudden death; causes of death have been identified:
Listeriosis:
Ewes becoming ill and down after being fed silage, these ewes presented very unwell with diarrhoea. A post mortem found inflamed intestines and a uterine infection after abortion. The pathogen identified was listeria
monocytogenes.
Important Factors:

• Listeria is present in silage which has been contaminated or exposed to the environment increasing silage PH.

• The edges of silage pits are most at risk of contamination.

• Listeria can cause nervous signs (circling, blindness, star-gazing), abortion and diarrhoea but not usually at the same time, all presentations can lead to death.

• Silage can be tested for listeria if there are concerns about its quality.
  

Superphosphate Poisoning:
Sheep were off feed, uncoordinated and eventually became recumbent and died after grazing a paddock which had recently had fertiliser application.
Important factors:

• Pregnant and lactating Ewes in late winter/spring

• Grazing paddocks within 1 week of applying fertiliser especially in fine weather

• Hungry sheep grazing short pastures

• Can present similar to milk fever and respond to calcium temporarily
  

Nitrate Poisoning:
A dead R2 found in a kale paddock, with others were acting drunk, had difficulty breathing and a few were recumbent. Diagnosis was made of nitrate poisoning; some recumbent cattle treated with methylene blue rapidly responded.
Important factors:

• Risk Period: low light (overcast), low temp, plant damage e.g. frosts, drought or after fert application

• Risk Crop: new permanent pasture (ryegrass), brassicas (turnips, kale, rape), cereal grasses e.g. green oats

• Critical factor is amount of nitrate consumed and how fast.

• Prevention: Don’t put hungry animals on risky crops and test risk crops nitrate levels.
  

Nitrogen testing kits are available to purchase or we can run the nitrogen test
for you before grazing potentially risky crops.

Newetrition - Fully Feeding Multiples

With scanning ticked off on most places, it's time to start thinking about prioritising feeding your multiple bearing ewes as they approach late pregnancy.

During the last trimester, the energy demand of the growing lambs increases rapidly. If ewes are not fed well over this period, several negative effects can occur. Colostrum quality and total milk yield will suffer, milk let down can be delayed, and lamb vigour and survival will be reduced.

About 7 weeks out from lambing:

• Ewes should be offered 1.7-2.4kgDM/day

• Avoid grazing below 900kgDM/ha (~2cm)

In the last 2-3 weeks of pregnancy (i.e. from set-stocking):

• Offer 3-4 DM/day, with the aim of them getting 2.5-3kg down the throat

• Avoid bulky feeds such as hay, and bulb crops (which contain lots of water)

• Aim not to graze below 1200kgDM/ha (~3.5-4cm)

Triplets:

• If you can offer post-grazing residuals of 1200kgDM/ha, there's no benefit to separating twins and triplets - the ewes can't physically eat more.

• However, if you can't offer all multiples that allowance, prioritise your triplet bearing ewes so that they are on higher covers.

Body condition score:

• Poorer conditioned ewes will produce up to a litre less milk per day than heavier ewes - this won't necessarily matter if she just has one lamb, but will have a big impact on twins or triplets.

• The good news is, if ewes are fully fed at the end of pregnancy, milk yields will be high regardless of body condition score - a win for lamb survival.

Time to Review your Animal Health Decisions for the Next Season

Challenging old habits, looking at new opportunities and rationalising what is required to ensure your livestock remain in optimal health is worth spending some time on.

We are presently conducting many animal health plan reviews on-farms. It has been pushed along somewhat by some food and fibre processors requiring a veterinary authorised animal health plan document. This aside, it is still a vital part of any farming business. We focus on what you want to focus on. Blending treatments, monitoring and performance targets to suit your program.

Topics include:

• Targeted use of drench products.

• How and when to monitor stock performance, drench efficacy, disease levels, mineral status.

• Best timing of vaccines.

• When to scan cows, test bulls, check rams, sort out dogs etc. for best results.

• Prescription medicine review and use of antibiotics.

There have been many motivational speeches and writings on the benefits of planning.

“A person who does not plan ahead will find trouble at their door” Confucius

“Always plan for the fact that no plan ever goes according to plan” Simon Sineek

“Give me 6 hours to chop down a tree and I will spend the first 4 sharpening the axe” A. Lincoln.

Choose one to motivate you to get your AHP sorted before scanning, fencing, shearing, lambing……. rolls around.

Pre-lamb Drenching

We sell quality products with sound advice, supported by a commitment to monitoring effectiveness. This pre-lamb we want you to maximise your return on investment by making sure you target the sheep that are going to need it most.

The sustainable worm control message is a targeted approach. Long acting drench to give the best return on investment in ewes under nutritional stress, multiples and in hoggets and 2 tooths. Managing an un-drenched population of ewes on farm is also best practice for delaying the onset of drench resistance. This undrenched population is generally better condition ewes and/or singles. Tagging undrenched ewes is important for monitoring. These ewes can be drafted at weaning to supply refugia to lamb finishing/hoggets. Ask your territory manager or Jeff Spillane for some refugia tags with your order. The fact is parasitism is always going to be a cost to production, so we need to ensure the drenches we have now continue to work in the future. I do encourage farmers to discuss with our Veterinary team how best to manage parasitism this pre-lamb.

To Do:

• Get a plan for worm control. It is also a good opportunity to develop a general animal health plan and rationalise prescription medicines.

• Work some refugia into your plan.

• Long acting drenches have worked well, but it is essential now to plan their use with application of sustainable management principles

Getting (stock) horses ready for the winter

Autumn, a stunning time of the year, but it also means that winter is just around the corner.

Tossing up what to do with that one colt foal that needs to be weaned but also needs a friend? If you castrate it now it can stay with the other horses without having colty behaviour and he can become a well socialized animal.

As we all know, the wetter autumn months can be a challenge with hoof quality and mud fever. Pull the horses shoes if not needed to reduce the amount of dirt in the horse's feet and keep them trimmed to avoid cracks in the hoof wall. Mud fever seems a yearly problem for some and never encountered by others. Try to keep the horse's leg free of wet mud, prolonged standing in muddy areas or badly churned up paddocks are high risk factors. Taping off gates or moving the horses along can prevent problems.

In preparation for winter we move the horses to better paddocks, feed extra hay, add a hard feed and some get rugged. All to compensate for the higher energy need to keep warm during winter. Often forgotten are the horse's teeth. Uneven wear and tear over the years reduces the horse's ability to chew the roughage provided, leading to poor energy extraction from the diet and often a drop in body condition score. Get your horses teeth checked by us before winter can save you a lot on the amount of food the horse needs over winter.

Artificial Insemination and Embryo Transfer in Deer

With the increasing attention on optimising performance in our deer herds, the use of additional tools should certainly be considered to improve reproduction performance. The Vet Centre works alongside breeding companies to develop a protocol specific for your farming operation. There are two different methods of improving reproductive performance - artificial insemination and embryo transfer.

Artificial Insemination (AI)

This involves a CIDR insert (controlled internal drug release) being used for 12 days and upon removal, an injection of eCG is given. All hinds are inseminated with AI 54-58 hours later. This protocol allows hinds in the programme to be synchronised and for all to be mated at the same time.

• The expected conception rate varies; between 65-75%. Most breeding places would sell semen to use. The majority of semen used is locally collected (in the region or elsewhere in NZ).

• The timing of AI is critical; it needs to be in the natural breeding season (late March/early April) and needs to align well with feed supply for your farm.

• Advantages include: using specific stags semen, not necessarily having to have the stag on farm, being able to use semen across more hinds to mention a few.

Embryo Transfer

This involves a CIDR insert (controlled internal drug release) being used for 12 days. In the days leading up to and after CIDR removal, hinds are injected with FSH every 12 hours. This allows hinds to superovulate and release more eggs than they usually would. They are then mated (naturally or via AI). Then 7 days after mating, the fertilised eggs (now embryos) are harvested from a single donor and inserted into numerous recipients.

• The conception rate varies too: 65-75% would be for most.

• The average embryos harvested from a donor is between 4-7 embryos. We usually work on having 6 to 7 recipients for each donor.

• Advantages include: shortening generational gaps, utilises better animals genetic and increasing their number of offspring and suitable for disease control.

Most people utilising these programmes would be velveting operations and/or trophy farms. However there is real potential to use this for venison operations. These could be considered for next season now. We would be more than happy to help.

Worm Control Options This Autumn

After a rain event it can take a couple of weeks for the sugars to re-establish in grass and it is also an opportunity for parasite larvae to re-emerge and have a chance to complete their life-cycle.

With a synchronised hatch of parasites and rapid development to infective stage, worm control in lambs/hoggets, 2 tooths and lighter mixed age ewes is beneficial. For the most part an effective combination oral drench is sufficient. For lambs drench interval needs to be every 28 days. DON'T LET YOUR DRENCH INTERVAL SNEAK OUT TO 5 WEEKS+, unless a FEC drench check indicates you can. If the worm burden has ramped up very quickly and pastures are heavily contaminated then persistent acting drenches can get your lambs out of a parasite rut. Exodus LA or Cydectin LA, are options but they will need an exit drench 70-90 days later. A novel drench is ideal (see below). For fine wool lamb traders long acting injectable drench is very appealing to keep them going well through the autumn.

Using a novel active drench on lambs/hoggets at some stage through March - May is recommended to clean out any resistant parasites that have accumulated. Zolvix plus and Startect are the two options. For farms where certain drench resistance has been diagnosed then targeted use of novels on ewes at pre-tup is advised (e.g. Startect to 2 tooths, light ewes).

In these conditions using adult cattle behind lambs or ewes behind calves is a very good way of maintaining lower levels of parasite burdens through a "wormy autumn".

Fly Pressure at its Highest

Dipping contractors and farms have been aware that effective measures need to be taken to protect against fly strike NOW.

Chemical choice is part of that. Plenty of chemical put in the right place is the other.

Cyrex combination dip is our top seller at this time of year because of the persistence of the cyromazine and the knock down effect of the spinosad. It is versatile for use in jetters, showers or plunge dips and even through watering cans for small lots. It can be used for spot treatment of strike also.

Cyrazin KO is an alternative to Cyrex. It is a combination of cyromazine and ivermectin. It is licensed for crossbreds and only for use in jetting races. The ivermectin is potent against maggots and lice and will also persist. It is stickier than Cyrex, so will last longer after rain.

Spray-on Options

Local treatment with spray-on options can offer significant advantages.

They are convenient to use, and put chemicals on in high concentration where they are needed.

Click Extra is the longest acting of these, and stock treated in November may need some additional treatment by March. Clikzin and Vetrazin Spray-on are shorter acting products very useful for re-treating keep lambs.

Beef Scanning

It is never too early for a scanning yarn. My small animal colleagues roll their eyes or slope away when we start talking about scanning rates, or the latest pistol grips and head set configurations.

For many beef producers they have realised the value in our scanning skills and can tolerate a level of in-depth discussion. "Being able to find those twin bearing cows is gold” one farmer said to me today. In order to do this, scanning between 40 and 100 days pregnancy is required. It is the same window in order to get pregnancies scanned into cycle groups, monitor bull performance and identify AI pregnancies.

So if you are interested in yarning about more than just wet-dry rates, get organised and book in your pregnancy testing now. Also let us know if you want BVD screening and tidying up horns done at the same time.

Ram Warrant of Fitness

A premating examination is an important part of any sheep breeding operation. Get your rams up to speed for the upcoming mating season, by not just palpating for soundness but giving them a comprehensive WoF. The visit provides a great chance to have an on farm discussion with your vet regarding your animal health needs for the year.

• Palpate rams for soundness

• Blood test suspect rams for Brucella Ovis

• Treat rams with scrotal mange

• Inspect feet - trim and treat lameness

• Vaccinate with 5-in-1 or 10-in-1

• Vasectomise any teaser rams

• Discuss the annual animal health plan for your stock

• Vaccinate working dogs

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.

Heifers

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.

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.

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.