Animal Health Considerations this Spring

The key to maximising lamb growth rates to weaning is maintaining high quality, high protein pastures with a legume dominance. This is rare period where lambs have the potential to achieve up to 400g/day growth. Prioritising twinning mobs and 2 tooth’s/lambing hoggets to the best paddocks will not only assist with maximising lamb growth, it will also ensure these younger growing ewes can continue to develop frame and put on condition after peak lactation.

Internal parasite control:

Pre-weaning tape drenching of lambs is a worthwhile exercise to maximise growth to weaning especially as nematodirus or tape worms are present.

Feet soundness:

If you see limping lambs you are seeing lost potential growth rate and reduction in weaning weights. Yes, many do self-cure, but if there is footrot in the ewes, this lamb lameness will linger for longer. Troughing will help, especially in the early stages. Tailing is a good opportunity to have a dedicated lamb foot checker. Blue spraying (Tetravet aerosol) infected feet is a really good way to get on top of lamb lameness. There are non-antibiotic aerosol options also for those on antibiotic free contracts.

Copper, B12 and Selenium to yearling and breeding cattle:

In growthy springs, there can be a requirement to supplement cattle with extra B12 and Selenium to ensure they optimise the spring conditions. A boost of copper can also be warranted for growth cattle (although ideally, they should have had this during the winter)

Multi-min (Se, Cu, Zinc and Manganese) is popular for breeding cattle/heifers. There is some data to show it has additional benefits for conception rates/embryo survival. Otherwise Prolaject B12 2000+Se is a popular choice at the moment.

Working Dog Health - Twisted Stomach

Twisted stomach or Gastric Dilated Volvulus (GDV) in dogs is a reasonably common, rapid onset, emergency affecting large dogs.  Often the dog is found dead in its kennel in the morning, however if noticed and treated in time then the outcome is often good.  The key to success is the quick identification of the problem and getting into surgery.  Often a few hours make the difference between life and death.

The biggest risk factor of a GDV is dogs that have a direct relative having had one, which is due to the size and shape of the chest.  Large chested dogs, especially huntaways are most likely to experience a GDV.  Other risk factors for GDV include large meals/feeding every second day, drinking large amounts of water rapidly, dogs that eat rapidly and lean dogs.

Signs to look for - off food, vomiting or unproductive retching, tight/distended abdomen, whimpering and other signs of abdominal pain, pale gums, lethargy/collapse.

Treatment involves stabilising the dog, which is usually in shock, then proceeding to surgery, where the stomach is untwisted and stitched to the abdominal wall preventing it happening again.  The outcome of the surgery depends on the amount of time that the stomach has been twisted and the extent of damage to the stomach, in areas that have lost blood supply.  If corrected with the stomach tissue having good viability, the prognosis is good.

Prevention involves surgery (Gastropexy) to open the dog up and stitching the edge of the stomach to the abdominal wall, which lasts a lifetime.  Preventative surgery should be considered in all huntaways, especially in dogs with a direct relative having had a GDV and in valuable dogs.

Scabby Mouth

As tailing approaches so does the most practical opportunity to vaccinate against scabby mouth.  Outbreaks observed in the past 12 months confirm it is still present and extremely challenging and labour intensive to treat.

• 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 of 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.

Vet LSD Drench: Do Ewes need extra vitamin E pre-lamb?

New Zealand research has shown benefits of extra Vitamin E with respect to lamb survival.  The vitamin E antioxidant is tied up with selenium, fluid dynamics within the foetus and lamb vigour.  Vitamin E is highest in green, growing leafy feed and it is lower in grains and stored feed.  So you can probably decide whether your ewes might benefit from the additional vitamin supplement prior to lambing..... or if it is worth leaving out?

Our Vet-LSD has been formulated (with vitamin A,C,D&E + Se + Cronium) and tested in New Zealand environments and widely used for over 15 years, hence why we endorse the use of it.  It is an insurance against a very easily fixed deficiency that can cost you production.  It can be mixed with most drenches, just dilute 1:1 before mixing (a 2ml concentrate dose becomes 4ml).  Then add that to an allocated amount of drench for the mob e.g. 500 ewes getting a 15ml dose of drench = 7500ml drench, + 2000ml of Vet-LSD(1000ml Vet-LSD:1000ml water mix).  Ewes then get a 19ml dose of the combined mix.  We have confidence that it does not interact with other drenches.  We recommend using it on the same day that you make it up.

Bearing Prevention

There is the vibe that it will be a "bearing year".  The things that can be managed are consistency of feeding for ewes carrying multiples.  4 day shifts were protective compared with daily shifts.  In one Otago trial it is assumed the gradual intake rather than 2 hours gorging and then sitting down for long periods, is why the longer shifts help prevent bearings.  Mid pregnancy shearing has been shown to be protective against bearings.  Iodine and salt appear to have some role in some cases, anecdotal evidence suggests LSD drench may also reduce bearigns.  Exercise, slope and extremes of body condition are involved.  Weight gain post mating and carrying triplets were among the biggest risk factors....but we can't do much about that now.  It is a frustrating and complex issue worth discussing with your vet.

Footrot News

The autumn conditions in the region have been great for grass growth but are also providing some challengeswith animal health. Warmth and moisture have provided good conditions initially for interdigital dermatitis (scald) followed by the spread of footrot in infected flocks. This challenge phase has resulted in moderate to high infection levels in many flocks, particularly in fine wool.

What can be done now: winter conditions will begin to limit the spread from sheep to sheep. Troughing in zinc sulphate is an effective control measure. Removing obvious cases from the flock will help but will not provide effective control until scald has stopped occurring.

It is important to use the winter as an opportunity to reduce the level of infection before the usual challenge period in the spring.

Once scald is under control:

• Tip sheep to identify chronic cases to remove from flock and treat
• Put "clean" mob on pasture that hasn't had sheep graze it prior
• Re-inspect "clean" and treatment mobs 2 weeks later.

This is a time consuming exercise but if completed well can reset the clock on footrot. Micotil antibiotic has shown in trial work to achieve high cure rates and we are seeing these repeated on farms around the district. Troughing can be effective if facilities allow sufficient contact time. Accurate identification of cases is important so we provide on farm training in correctly diagnosing footrot. Contact your local Vet Centre for any advice or development of a footrot control plan.

Autumn Worm & Feet Challenge for Sheep

Because of the warmer, moist conditions through April larval challenge has been high.  Lamb drench interval needs to remain at 28 days.  Use the most effective drench available.  Using a novel active such as Startect or Zolvix once in late Autumn is gaining momentum.

There is merit in using long acting drenches to grass wintered hoggets/fine wool lambs in these conditions.  2 tooth ewe faecal egg counts that have come through the clinic have generally been high and has warranted pre-tup drenching this year.  It would be prudent monitoring FEC at mid pregnancy stage.

Feet and footrot spread has been rampant this Autumn where flocks have come through spring with more than 5% infection - this can double every 2-4 weeks.  Those farms that put in the effort during last year's dry periods have reaped the benefits this year but vigilance is still required.  It has not been a good autumn for inspecting feet and attempting to make "clean mobs" because of the rampant spread.  The Micotil treatment system has been working well to salvage ewes and break the cycle of infection.  Footvax may be a tool more farms employ this winter/spring.

Weaner Calf Animal Health

At weaning give a combination worm drench orally or Eclipse E injectable or Eclipse pour-on.  Whilst calves are on their mothers' milk based diet internal parasites do not cause many issues but once weaned it is a major handbrake on pasture bases growth rates.

Minerals for weaners: it is hard to go past long acting selenium (Selovin LA) as a way to reliably sustain levels for the next 12 months.  Copper is also important.  Copacap copper bullets are longer acting, but Coppermax injection is a good alternative going into the winter, especially if wintering on brassicas.  Covexin 10 in 1 (or at a minimum Multine 5 in 1) vaccine is well justified at weaning and again 1 month later.  These vaccinations are critical if going onto fodderbeet.

Summary Recommendation at weaning: 1 x drench, 1 x mineral (selenium), 1 x vaccine (1st covexin). 5 weeks later: 1 x mineral (copper) 2nd covexin and drench if required.

Waitaki Valley Update - Sudden Death Cases

We have recently investigated several cases of sudden death in lambs that were diagnosed post mortem with pleuropneumonia, a very common problem typically occurring in late summer/autumn.

The economic impact of pneumonia is significant, not only due to lamb deaths but also with poor growth rates and downgrading of carcasses at slaughter.  Heat stress has been identified as a major risk factor, specifically open-mouthed breathing and panting, which allows infective organisms to bypass the protective defenses in the nose.  Other associated causes include dusty conditions, lack of shade, excessive dog use, high endophyte grasses and dehydration.

Shearing on the same day as weaning, with its increased stress and crowding also increases risk.  However, set stocking lambs after weaning has been shown to have a protective effect.  Fine wool breeds appear to be less susceptible, possibly due to increased heat tolerance.

Treatment is challenging however best results for prevention will occur from ensuring strong immune defenses, through good nutrition and disease control.  Giving a dose of Livestock Survival Drench has also been reported to reduce the incidence of pneumonia.

Sheep Keds

Recently we have seen an increased presence of Keds becoming an issue on farms predominantly in the Omarama, Palmerston and Ranfurly areas, particularly in fine wool sheep.  Due to compulsory plunge dipping of all sheep with organophosphate dips, in the past, Ked populations around the country were greatly reduced.  However some populations have started to re-emerge.

Sheep Keds are blood sucking wingless flies that cause irritation leading to fleece damage by rubbing as well as reduced growth rates and wool discolouration from digested blood in faeces.  Anaemia due to blood loss from high burdens is possible especially in young lambs.

Dipping with a product that has persistent activity for longer than the time it takes for pupae to hatch is required to kill all newly emerged adults.

It is important to form a plan with a combination of dipping and drenching to have the best result in eradicating Keds from your farm.  Best results come from using Cyrex for fly control as well as a lice dip that is effective against Keds.  This will either be a pour-on off shears or jet/shower dip with at least 4 weeks wool on.  Principals for control, as with lice control, are to have complete musters, secure boundary fences and quarantine dipping of any bought in stock.  To prevent growth limiting effects on lambs each drench should be either a Matrix or Switch, containing abamectin.

For any questions or to form an eradication plan talk to one of our Vets at the Blue Cross Veterinary Centre,.

Scheduling Beef Pregnancy Testing This Season

With the good spring conditions had around the district beef cows should be in good condition running with the bull.  The best way to manage how mating pans out is to correctly time pregnancy testing to allow ageing of pregnancies.

Aged pregnancy testing 6-8 weeks after the end of mating gives information allowing management decisions to be made:

• Late calvers can be kept separate during calving allowing better feed and mob management.
• It also provides a culling option for late calvers.
• Allows early identification of non-performing bulls and other reproduction opportunities and failures.

Sheep Measles

Occasionally we hear of slaughter animals with sheep measles.  These are hard white cysts found in the muscle tissue of sheep or goats.  It is caused by the tapeworm (Cysticercus ovis).  Although there is no associated human health risk, blemishes in the meat can result in a carcass being downgraded or condemned.

The parasite requires both dogs and sheep to complete its life cycle.  Dogs ingest the tapeworm (called Taenia ovis in dogs) in contaminated meat and then spread infection via eggs in the faeces.  Sheep become contaminated after ingesting eggs as they graze.  The eggs then penetrate the gut wall and move to the muscles of sheep where they form cysts.

CONTROL OF SHEEP MEASLES:

Regular worm treatment for dogs:

• Monthly treatment with a wormer containing Praziquantel (e.g. Droncit)
• Every third month this should be swapped for a treatment that contains ingredients active against other worms (e.g. Drontal)
• All dogs that enter the property should be treated (i.e. pets, friends & family, other visitors such as hunters)
• Join our worming programme and worm treatments will be posted out monthly.,

SAFE FEEDING OF SHEEP MEAT:

• Freezing is most practical
• Core meat temperature should be reduced to at least -10 degrees C for 10 days
• Date meat when placing in the freezer so it is easily identified
• Offal also needs to be frozen if being fed to dogs
• Butcher fresh carcasses away from dogs so they cannot access fresh meat
• Don't let dogs scavenge on sheep carcasses

Pre-weaning Drenching - what does the science say?

We often get asked whether it's worthwhile drenching lambs pre-weaning?  Survey work showed that up to 90% of farmers routinely drench their lambs at this point, targeting perceived benefits of better growth rates, less dags, and less pasture contamination.  Unfortunately any increase in drenching also carries an increased risk of selection pressure for resistance.  It is therefore good to have some clear evidence of the benefits of such strategies so that the pro's and con's can be weighed up.

In 2010, to answer this question, Beef+Lamb NZ funded a trial looking at the effects of a pre-weaning drench (normal roundworm), with or without a tapeworm drench (+ Praziquantel).  Both of these were compared to a control group that received no drench.  The tapeworm question was an interesting addition - it had long been thought that tapeworm didn't adversely affect growth.  However some more recent studies had challenged the theory that tapeworms are benign, and farmers also routinely report that they believe tapeworm causes a smelly scour that is attractive to strike flies.

Key Findings:

Weaning Weight

• Lambs given a roundworm drench were ~0.5kg heavier at weaning than the control group
• Lambs given roundworm + tape drench were ~1kg heavier at weaning than the control group
• Lambs given the additional tape drench showed a 24g/d liveweight gain advantage over a straight roundworm drench

Dag Scores

• There was a dag reduction response to a roundworm drench.  This response was slightly better when a tapeworm drench (praziquantel) was included.

Overall, these figures did support the feeling of farmers that a pre-weaning drench will lead to heavier and cleaner lambs at weaning.  The addition of a tape drench at this point may be beneficial.  Most of our clients opting for a Tape option would use "First" Drench (BZ, Levamisole + Praziquantel).  As with all drenching questions, any gains should be weighed up against the increased risk of resistance.  Our vets can help you examine these pro's and con's for your farming system, so make use of them!

Antibiotic Use In Production Animals

New Zealand farm systems use very little antibiotics compared with overseas, housed animal models.  However, it is sometimes worthwhile reminding ourselves of the value of modern medicines to ourselves and animals.

The introduction of penicillin to society in the post WWII era was a revolution for human and animal health.  What are now simple procedures were life threatening or not possible 60 years ago.  Emergence of antibiotic resistance is a reality and we know the risk factors that encourage it.  So examining our habits around its prescription, use and application is justified.

y message to farmers is:

• Get a diagnosis.  It has become a pattern of behaviour that we just "cover it with antibiotics" just incase or for lack of any other option.  Diagnosis is not always straight forward, but veterinary involvement, either on-farm or even over the phone should be sorted before treatment if unsure.
• Use the correct dose.  For example, for penicillin the standard label dose is not always appropriate and needs to be higher.
• Do a full course of treatment.  One dose is often inadequate to clear an infection.  This shortened course is a real risk factor for bacterial resistance to emerge.  Treat for "two days past clinical resolution" is a standard line.  There are a wide range of antibiotics that have different dose intervals ranging from 12 hours to 12 days.
• Check expiry date.
• Explore other options and/or prevention measures.

For example, conditions like footrot, there are things that you can do around troughing and inspection of the infection that will improve the efficacy of your antibiotic treatment or even reduce the numbers needing treatment.

Illnesses that require antibiotics will always occur, but many have a preventable aspect to explore.  Veterinary involvement is always worthwhile. 

We always need to challenge what we are doing with our livestock practices and look for efficiencies.  Our habits around antibiotic use are an important area to evaluate not just for the future health of animals but also for human populations.

We have a 3 tiered system of prescribing prescription drugs.  Over the counter, annual prescription renewal and specific condition veterinary consultation.  I hope as farmers you understand our need for these processes and you are not unduely inconvenienced when requesting antibiotics.

Spring Issues for Beef Cattle

The sun has been shining up the Waitaki Valley and spring is well and truly in the air with a decent growth of new grass starting to come through.  Unfortunately, this can pose a potential risk to soon to be calving beef cows as this fresh, fast growing spring pasture often has a low magnesium content.  Lactating cows have an increased demand for magnesium that consequently may not be met.

Inadequate magnesium levels lead to nervous signs such as excitement, bellowing, uncoordinated movement (hence the name Grass Staggers) and convulsions, rapidly progressing to death if untreated.  In extreme cases, the only sign of a problem may be cows found dead.

Treatment is possible by injecting a magnesium solution under the skin, but preventing the problem is always better.  This can be achieved by supplementing cows, starting 2-3 weeks prior to the risk period.  The addition of magnesium to supplementary feed or the administration of slow release capsules are suitable options.  Our vets can advise you on the best option for your farm.

Spring Larval Challenge

Spring is also a key time to consider drenching yearling beef stock as pasture larval loads peak during warm and wet weather, resulting in high levels of infection.  Once ingested, the larvae multiply and grow, causing gut damage which leads to scouring, suppressed appetite and diminished growth rates.  Using an effective combination oral or pour-on drench that targets Cooperia is recommended.  There are several oral options such as Matrix Minidose, Alliance or Arrest C.  Eclipse pour-on is the convenient option.

Cattle Lice

This is the time of year we see scratchy cattle appearing with lice infestations.  Lice obviously cause a lot of irritation and can be associated with ill thrift and cattle wrecking gates and posts, etc.

A salvage treatment early spring may be required (better to treat in early winter).  The critical thing is to dose all cattle with an effective dose and product.  Tempor will treat only lice, whereas many worm drench pour-ons and injectable drenches will also kill lice, but they are not all equal.  Genesis, Eclipse, Dectomax and moxidectin pour-ons are generally very good options.

Long Acting (LA) Ewe Anthelmintic Products

LA ewe products are commonly used pre-lambing, and have many advantages for both EWES and LAMBS, including:

• Improved ewe condition - through increased feed efficiency and improved appetite
• More milk and less body weight lost during lactaiton
• Less dags and improved lamb weights
• Significant benefits for twin bearing 2-tooths.

The production benefits of LA ewe products must always be balanced with the risk of drench resistance - their use can increase selection for resistant worms on your property if not used strategically.  Using best practice guidelines mitigates resistance pressure and extends the longevity of existing drench actives.

Best Practice Guidelines for LA Product use:

• Use an effective product: The only way to know how effective a drench family is on your property is to perform a Faecal Egg Count Reduction Test (FECRT).  This will allow sustainable product use which will also maximise production.
• Utilise Refugia:  Utilising refugia involves not treating selected animals on a property to ensure a balance of susceptible larvae are present on the property.  This is a technical process and advice from a vet should be sought before proceeding.
• Faecal Egg Counts:  Check if capsules or LA injections are still working on your farm.  Our veterinary policy is to test all farms we have supplied capsules or LA injections to, at our cost, around 60 days after administration.  If eggs are detected, use an exit drench or triple active at the end of the long acting treatment.
• Use a triple combination or novel active (Zolvix/Startect) drench on lambs at weaning.
• Exit Drench with a novel drench or triple active at the end of the long acting treatment.

Products on the market:

Bionic:  A 100 days combination capsule with continued release of abamectin and albendazole, plus selenium and cobalt.  Withholding time is 126 days.

Extender SeCo:  A drench capsule which releases albendazole (white drench) for 100 days, plus selenium and cobalt.  A priming dose of an effective combination drench must be given to the ewes when capsules are inserted.  Withholding time is zero.

Exodus LA, Cydectin LA:  These products contain a long acting form of moxidectin.  It is active against Ostertagia for 112 days and Trichs for 42 days after a single injection.

Cydectin Injection including Eweguard:   A moxidectin injection that is active for 35 days against Ostertagia, and at least 7 days against Trich's.  It is best used 2-4 weeks pre-lamb.  Withholding time is 28 days.

Ewe Wastage - Johne's Disease

Johne's is present on 70% of farms and has contributed to 22% of total ill thrift diagnoses in NZ in the last 5 years, followed closely by Trace Element deficiency, showing us that it's a problem in New Zealand.  Johne's disease is caused by a bacteria that infects lambs while suckling or grazing, persisting in the gut and flaring up at stressful times such as a pinch of feed or shearing.  Ewes subsequently lose a significant amount of condition and eventually die.  Vaccination with Gudair as a hogget markedly reduces the onset of disease and contamination of the farm with the Johne's bacteria. 

Phil Smith runs 8500 Romney-Merino crosses just outside Naseby and has been vaccinating his sheep for Johne's for 10 years.  Prior to vaccination, Phil was losing 200-300 sheep each year, which was attributed to Johne's.  Once vaccination started there was a massive improvement in the hoggets the following year, ewe wastage continued to drop yearly until all animals were vaccinated.  Another appreciable difference to Phil was that there were no tail enders slowing down droving and a lot less faecal staining of wool in the yards at shearing time.  A contractor experienced with use of Gudair vaccine jabs all the hoggets on the conveyor in late September which covers them for life.  Phil still benefits from reduced ewe wastage and improved production and welfare.  There is no longer restrictions with slaughter of vaccinated animals.  More details will be presented at our roadshows including returns on investment.

Mated hoggets - early pregnancy weight gain essential

Looking at the financial returns from hogget mating, we have demonstrated that better returns can be made by mating fewer, well grown hoggets (taking a cut-off weight of 40-42kgs) than putting the rams out with all hoggets and seeing what takes.  Once mated, from June - July mated hoggets still need to be a priority.  This is the only chance until their lambs are weaned that they can really grow without the drain of heavy pregnancy and lactation.  Hoggets need to grow at 100g/day for the first 100 days of pregnancy.  Work on an allocation of ~1.6kgDM/hd/day.  This is important to build a decent frame for lambing.  When farmers who hogget mate end up with poor 2 tooths, it can be because they are not growing out during pre-tup to pre-lamb (March to July) and/or post weaning (January to March the following year).

Very fast growth rates (>250g/day on forage crops) may be detrimental to ovulation or lead to large birth weighty lambs and more dystocia.  Red clover and lucerne with leaf spot may reduct ovulation.

Animal health wise, parasites can be managed effectively through prudent use of bionic capsules or long acting injection.  B12, Selenium and iodine are important also.

There are a number of things under management control that can make a big difference to your hogget mating outcome.  Talk to us to go through a hogget mating check list.

Animal Health The Key To Success With Fine Wool Lambs

The essence of successful fine wool lamb finishing is keeping the worms out, the feet sound and the guts right.

The gut microflora on fine wool lambs is more delicate than others.  Smaller lambs (less than 23kg) are at much higher risk of scouring issues.  There isn't the scope to debate the virtues of enzyme drenches or explain this complex here, suffice to say avoiding the scrubbers will reduce wastage.

Fine Wool Lamb Parasite Management

The way merino lambs camp and graze together with an immature immune system, means they can be more prone to internal parasitism.  A solid preventative drenching program from the start is vital.  Woe betide skipping or stretching out a drench in the autumn....

Many find a SeCo capsule or LA injection takes care of the autumn worm issues.  An exit drench of Zolvix or Startect is a prudent measure to ensure any resistant worms are not carted through the winter.

Clostridial vaccines (2 shots) are a no brainer.  These valuable animals (as pointed out above) are the highest risk because they're on your property longer, have several feed changes and are expected to grow fast in the spring after shearing.

Fine Wool Lamb Feet Soundness

Having a plan and set up for managing feet and starting with inspecting feet when they first arrive is advised.  You can't take chances with footrot.  If an infection is left to spread in mob it can really smash your margins and making running these animals a misery.  With planning and good management fine wool hoggets can do very well on improved pastures.  Because of the dry summer this year, there have been less footrot infected lambs at weaning, but the back end of autumn with dewy conditions footrot infection can take off in hoggets if not managed.

For more specific details about animal health and feet management for successful fine wool finishing contact the Veterinary Centre.