Farm Animal Information - Cattle
- Bobby Calves
- Cattle BVD
- Calf Disbudding
- Calf Scours
- Facial Eczema
- Livestock Poisoning
- Pregnancy Testing
Bloat is the common name for ruminal tympany, abnormal distension of the rumen (stomach) of cattle. It is caused by excessive retention of the gas produced by normal digestion that is usually belched, but in cases of bloat is trapped usually as a foam in the rumen. Severe bloat causes extreme distention of the stomach, resulting in pressure on all other internal organs, and can quickly lead to death
Control of bloat includes pasture and grazing management, anti-bloat capsules, anti-foaming agents and as a last resort the old emergency rumenotomy (stab!).
Higher dry matter levels, hay feeding, longer rotations, species of plants grazed, continuous grazing and careful fertilizer application can all greatly aid in reducing bloat.
Include: oils and fats, marlophens and detergents (alcohol ethoxylates and pluronics). These agents act by breaking down an already formed stable foam. Fats, oils and marlophens are safer, but slow to work and short-lived. Detergents are faster acting, and much more persistent but can be toxic if overdosed or given to calves.
These prevent a stable foam forming by changing the proportions of microorganisms in the rumen and hence the way feed is broken down. These compounds also have the added benefit of increasing feed conversion efficiency.
METHODS OF CONTROL
SLOW RELEASE CAPSULES (Monensin)
Give 100 days cover.
· Generally cost effective.
· Low time input; more peace of mind.
· Need to administer 5-7 days prior to expected bloat challenge.
· May need to use an anti-foaming agent as well during very severe challenge or in 1st 5-7 days.
· Toxic to dogs and horses.
DRENCHING (TERICS, PLURONICS)
· Can vary dose rates according to the challenge.
· Twice daily in moderate – severe challenge.
· Unsuitable in some sheds.
· Take care not to overdose.
· Never use detergents in calves – use oils.
· Low price option.
· High labour input.
· Use in the dry period, for heifers, in non-drenching sheds etc.
· Made of oils, emulsified oils and fats, detergents with sticking agent.
· Higher dose of active ingredient therefore higher cost.
· Must spray total area.
· Can only use 12-24 hours ahead.
· Break-feed. No back-grazing.
· High labour input.
This problem costs New Zealand an estimated $45 million annually making it one of the most costly on-farm problems. Pasture bloat happens when cattle graze succulent, rapidly growing pastures in the pre-bloom stage. These pastures are high in protein, water and starch, but low in fibre. Clover content is often high but bloat can occur on pure Ryegrass too. In general, the more fertilised and higher producing a farm becomes, the higher the risk of bloat.
· Most detergents can be used.
· Use trough or inline dispenser.
· Alcohol ethoxylates are more palatable.
· Introduce early: 2-3 weeks before bloat is expected.
· Need to ensure no access to untreated water.
· Treat milking shed troughs.
· Ensure easy access to treated troughs.
· Increase concentration of detergent when wet weather reduces water intake.
· Increase concentration 12 hours before grazing a dangerous paddock.
· Less reliable. Water intakes vary for many reasons.
· Useful for background control; switch to pasture spraying or drenching during danger periods.
· Paraffins, tallows.
· Frequent failures under challenge.
· Some application for dry stock and beef cattle.
· Some animals underdosed and at risk.
Nothing yet beats drenching in severe bloat conditions For the best bloat prevention under sever challenge take note of the following:
· Use an alcohol ethoxylate active bloat drench like Blocare 4511.
· Drench twice a day at maximum dose of active plus very important to use plenty of water.
· As challenge lessens, reduce active as per label but keep water volume constant.
· Rumensin Bloat Capsules are okay for the prevention of moderate to medium bloat challenge but drenching should be done during severe challenge.
· Bloat Blocks and trough treatments are marginal but are better than nothing.
THE INEVITABLE BLOAT PANIC
· Have an emergency kit ready – knapsack and gun set on high dose ready made up detergent or bottles with individual doses ready to go.
· A sharp bloat knife – double bladed with guard plate.
· Maybe a rumen injector for “marginal” cases.
IF YOU HAVE TO STAB
· For example: if the cow can’t walk, is having trouble breathing / is collapsing (even if the cow is down and not breathing) – stab her – you’ve got nothing to lose and she may recover.
· Use a knife with hand guard, otherwise you risk severely cutting your own hand
· Stab on the left side one handspan down from the lateral processes of the vertebrae (short ribs) and one handspan in front of the hipbone – one firm, clean stab of a decent size (5-10cm) to let the froth out.
Once the stomach (rumen) wall collapses and falls away from the body wall, leakage will occur and peritonitis will start to develop. Call the vet as soon as possible after the stab, we prefer to stitch wounds around 2-4 hours after stabbing. If it is sutured within a few hours of the stabbing, the peritonitis won’t get the chance to really get going and she’ll have a better chance of recovery.
· No one method of bloat control is 100% reliable.
· Bloat stab cows generally survive, but can be wasted in terms of that season’s milk production.
· Aim to prevent, not treat!
BVD – Common, costly and controllable.
BVD (Bovine Viral Diarrhoea) is one of the most common and costly diseases in New Zealand cattle.
The problem with BVD is that many of the losses it causes are not obvious; your cattle may have this disease and you may not be aware of it. In NZ about 15%-20% of dairy herds and 65% of beef herds are infected with BVD, and most beef and dairy herds will be infected at some point in time. The infection causes scouring and ill thrift in young stock, infertility, increased somatic cell counts and production losses in adult cattle.
When breeding cows are infected you probably won’t see any obvious ill-health effects in that breeding cow. However the effects on fertility and on the unborn calf are profound, including low in-calf rates, abortion, stillbirths, birth of “dummy calves” and the birth of persistently infected (PI) carriers of BVD virus.
The economic impact in dairy herds has been estimated at between $35 and $87 per cow per year in an infected herd. In beef herds economic losses are associated with ill thrift in young stock and on average, a 5% increase in empty cows.
Control of BVD is relatively simple, involving testing and culling of PI cattle, biosecurity measures to keep the virus out, and vaccination. Advances in laboratory diagnosis mean that it is now simpler and more cost effective to diagnose and eradicate BVD from a herd than ever before. Tests can be done on individual animals and on bulk milk samples. Biosecurity measures include testing of all incoming stock onto the farm. An important group to test is breeding bulls – we recommend that all breeding bulls are tested for BVD virus before purchase. Vaccination may be recommended by your vet as a simple and cost effective measure for controlling BVD on your farm. Ultravac® BVD has been proven to be highly effective at preventing losses due to BVD, including protecting the foetus and preventing the birth of carrier (PI) cattle .
The first step in BVD control is to determine the BVD status of your farm, through appropriate testing. Then it’s a matter of working together with your vet to put in place a long term management plan for control of the disease.
For further information on BVD control, talk to your vet today.
Cattle with horns are dangerous to people and other animals and are removed for welfare reasons. The process of removing horns in young cattle is referred to as calf disbudding or calf dehorning. This is a service provided to our farm clients and lifestyle block holders by Cambridge Veterinary Services.
Calves are generally disbudded by a team of qualified staff including a veterinarian, when they are between 2-6 weeks of age (less stressful to the calf and the handler). The procedure involves heavily sedating all calves and the administration of local anaesthetic to the surrounding area. Additional pain relief in the form of NSAIDs can also given upon request. This method of disbudding ensures the horn buds are removed effectively at the correct time, with a minimum of pain and discomfit to the animal.
While the calves are sedated, ear tags can be easily applied, navels can be checked for infection and extra teats that will interfere with future milking can be removed. Calves can also be given their first sensitizing dose of clostridial 5 n 1 vaccine.
Treatment of Calf Scours – Made easy
Diarrhoea (scours) is the single most important disease of the neonatal calf and is responsible for the greatest economic losses in this age group.
Calf scours is a complex disease; the causes of which are well known (nutritional, rotavirus, E.coli, cryptosporidia, salmonella, coccidia, corona). The resulting diarrhoea leads to a loss of electrolytes and large volumes of water in the faeces, damage to the lining of the gut with reduced milk absorption and changes to the gut bacteria.
Irrespective of the cause of diarrhoea, electrolyte replacement therapy remains the primary treatment of choice. Antibiotics & gut protectants (of which there are many) play a supportive role.
Scouring calves can be divided into 4 groups according to the degree of dehydration present;
• Bright and alert with a strong suckle reflex – group 1
• Weak suckle reflex, standing or sitting quietly – group 2
• No suckle reflex, depressed, unable to stand – group 3
• Collapsed, lying on side, no suckle reflex, death imminent – group 4
The presence or absence of the suckle reflex will primarily determine which route the fluid will be given; orally or intravenously.
Death generally arises when fluids/electrolytes are given too little or too late.
Group 1 & Group 2 Calves
Oral replacement therapy is highly effective with 95% of calves surviving if fluid therapy is administered early and continued until full recovery. Fluids and electrolytes can be given orally either by a bottle/teat system or oesophageal feeder (see below for instructions on how to use the oesophageal feeder).
Aim to give 7-10L’s/day divided into 2 litre feeds – that’s 4-5 feeds/day! This sounds like a lot of fluid (and work) but remember we need to replace fluid lost through ongoing diarrhoea, replace the deficits already incurred and give the calf fluid for daily maintenance requirements.
There are a number of excellent commercially available, carefully balanced electrolyte replacers on the market for treatment of calf scours. All of these products contain glucose or a similar material, sodium chloride and other electrolytes. Giving straight water does not work. Consult with your veterinarian regarding the appropriate oral electrolyte product for your needs. Always follow the label mixing instructions–do not add too much powder to the solution as this may further harm the calf and unnecessarily add to the cost of treatment.
Milk is also required to provide the calf with an energy source but milk should not be mixed with the electrolytes as this may affect curd formation within the abomasum. A feeding interval of 3 hours is needed between electrolyte/milk feeds. The table below can be used as a guide to fluid therapy.
Group 3 & 4 Calves
Once the suckle reflex has been lost and the calf is down IV fluid therapy is therapy is essential. Contact your vet immediately for further assistance. IV fluid therapy can improve the status of the animal quickly (if administered early). This will return the animal to a group 2 calf and fluid therapy can continue with an oesophageal feeder.
Fluid therapy continues until the scour has resolved.
Faecal samples are often requested/collected from sick calves to differentiate a nutritional scour from an infectious scour and to determine the causative agent. By identifying the pathogen responsible for disease we are able to recommend product specific treatment options, effective disinfectants & vaccination programs. We can also develop a plan and implement strategies to minimise further exposure and disease. Advances in laboratory diagnostic tools means we are able to have results back, in many cases, on the same day.
SUPPLEMENTARY TREATMENT PRODUCTS
Many products exist on the market that aid in calf scour recovery and as suggested should only be used to supplement therapy.
Appropriate rehydration is essential.
Antibiotics: The use of antibiotics (scour ban, pink tablets, injectables etc) for calf scours is controversial however if blood is present in the faeces antibiotics are generally warranted. Speak to your vet.
Binding agents: Binding agents are generally some type of plant fibre/pulp that viruses and bacteria will “stick” to. In this way the infectious agents will preferentially bind to the fibre instead of the intestinal wall and will be passed out in the diarrhoea. The binders also slow down the rate of passage of fluid through the gut, giving the intestine more time to absorb water back into the calf’s system.
Antibody powders: are now available for scours caused by either Rotavirus and/or Cryptosporidia. It can be used to prevent and treat specific calf scours however its use is only justified upon a confirmed faecal diagnosis of either one or both of these pathogens.
Products are also available that reduce the severity of scours and the excretion of infective eggs into the environment. Talk to your vet.
WHEN DO I NEED HELP?
If your treatment methods are not working, contact your veterinarian immediately for additional help. If more than 5% of your calves are scouring and require treatment, you need help. If death is greater than 2% due to calf scours contact your veterinarian. Your veterinarian can submit refrigerated (not frozen) faecal samples to the lab and receive answers, in most cases, on the same day. Freshly dead calves can also be examined to determine the cause of the diarrhoea and to aid in determining those factors needed for prevention and treatment in your herd.
If you wish to discuss the management of calf scours further, require additional assistance, or need advice on animal health issues feel free to call your vet.
NURSING CARE AND PREVENTION
The most important aspect of control focuses on minimising predisposing factors and implementing strategies to prevent them from occurring on farm.
• Good colostrum management is critical to prevent disease– 2L’s of colostrum by bottle or feeder within 12 hours of birth.
• Prompt identification of sick calves, removal to hospital pens, and administration of effective, vigorous treatment. Don’t forget calf covers for warmth.
• Establish an isolated ‘hospital’ shed to minimise the spread of disease from infected animals. Once the calf has recovered it does not go back into the ‘healthy’ shed.
• Care should be taken to prevent the risk of personnel carrying contaminated material from the sick calves to animals in healthy pens. Consider establishing foot baths. Treat & feed the calves in the hospital pen last.
• Meticulous attention to hygiene is critical. All utensils used for feeding calves and storing milk should be thoroughly cleaned on a regular basis. Utensils used with sick calves should not be used for healthy calves.
• Avoid mixing calves of different ages. Use an all in/all out system.
• Clean (with an effective, safe and appropriate disinfectant) spraying the pens on a weekly basis and/or spell pens between batches of calves.
• Provide clean, fresh drinking water in drinkers that cannot become contaminated with faeces.
• Handling of CMR and provision of high quality compound feed and roughage is important.
• Provision of appropriate housing.
• Clean, new bedding annually.
• Vaccines are available for some pathogens – discuss with your vet
HOW TO USE AN OESOPHAGEAL FEEDER
An oesophageal feeder is a long flexible, plastic tube that screws onto a larger plastic container that holds the electrolytes. Prior to passing the feeder, always make sure the probe and the container are thoroughly clean (wash it after each use so it is clean for the next time). When administering the electrolyte fluid make sure it is at body temperature 35-40 degrees.
Position the calf so that it is either standing or sitting up on its chest.
Gently lift the animals head up to insert the tube. If the calf struggles, lift the front end up so it is sitting on its haunches; you can restrain the calf easily that way while you lift its head to insert the tube. If the calf is standing, back it into a corner (or have someone hold its back end), step over its back so you can hold the head and neck between your legs, and pull the head up with one hand under the lower jaw—so you can insert the tube with your other hand.
Gently put the tube into the side of the mouth. This is easier (and easier on the calf) than trying to force it into the front. Then aim it straight and slide it over the tongue to the back of the mouth and into the throat. The calf should swallow it as you move it back and forth and apply gentle pressure. Make sure the tube is not forced into the windpipe; the calf must be given a chance to swallow as it is pushed down. Stop pushing for an instant and place your fingers on the outside of the neck (front of the throat), to determine where the tube is going. You can feel or see the bulb end of the tube slip down the throat and into the oesophagus.
If you can see or feel the bulb (above the windpipe), you know it’s in the proper place and it’s safe to continue pushing the tube farther down. If you can’t see or feel it, or the calf is coughing, or there are puffs of air coming out your end, it’s in his windpipe; you must take it out and start over. Be sure it’s in the oesophagus and fully inserted (the bulb down close to the stomach) before you tip up the container or release the fluid into the tube. Hold the calf so it can’t struggle—or the tube may come partway out and allow fluid to get into the windpipe. Once positioned, the container can be lifted and the entire contents can be allowed to drain into the rumen.
Prevention is by management as well as zinc therapy or pasture spraying.
Beware – we usually face a LONG facial eczema season
Zinc based prevention relies on dosing animals with zinc salts, either zinc oxide as a drench or water treatment with zinc sulphate, or the zinc bolus.
· Dry stock can be dosed at twice weekly or even weekly intervals.
· Zinc dosing can be expected to reduce, but not completely eliminate FE outbreaks.
Please contact us for details on this procedure eg how much zinc oxide to use for pasture spraying.
Pasture spraying with fungicides including “Xspore” and “Mycotak / Mycowet” system is also possible. This is the best option for owners of Alpacas.
Please enquire about these. Careful planning is required.
Plan for a long season, maximum of three capsules can be given.
These are long acting boluses that give good cover in sheep and cattle. There are different sizes depending on the animal’s liveweight. Note new size for small calves. These are not suitable for Alpacas as they dissolve too quickly leaving animals unprotected.
There are three calf bolus sizes for 90 – 130kg, 130 – 175kg and 175 – 250kg liveweight, i.e. weaner to yearling cattle, which provide protection for a minimum of four weeks. The cattle bolus for animals 250-400kg has the same length of action. Re-dose in 5th week following initial dosing. A maximum of three boluses may be given.
Note the minimum weight for bolus application and check liveweight.
The bolus contains zinc oxide in a compacted form and is covered by a wax capsule open at one end. The zinc is slowly released from this capsule to provide the prolonged protection. Damaged or broken capsules cannot be relied on to provide as long a period of protection so care must be taken in handling and administering capsules. They may also give toxic doses of zinc and should be discarded.
These capsules cost $4.25, $5.20, $6.00 and $9.00 incl GST respectively.
Lamb capsules are $2.00 incl GST and Sheep Capsules $2.60 incl GST
SUPPLY OF ZINC PRODUCTS FOR THIS SEASON
Most years there seems to be supply problems with one zinc product or another. In previous years the massive increase in demand for Time Capsules led to delays in delivery of product from the manufacturer. In other seasons shortages related to drenching and trough products.
Supply companies import massive tonnages of product each year. The increase in areas of the North Island affected by facial eczema challenge and the current weather patterns mean supplies may be exhausted far earlier than anyone can anticipate.
Zinc is a product that cannot be just sourced and flown in to New Zealand in five minutes.
It is false economy to risk buying zinc products only as you need them and we recommend either forward ordering or forward purchasing your requirements based on individual farm history and stock numbers from whoever your retail supplier may be.
Cambridge Vet Services can offer a full range of FE prevention products including the Agrifeeds Global range and Time Capsules.
Cattle Zinc Drenching
Long Term Dosing Stabilised Drench eg Global Supa-Zinc
Mix 1kg zinc oxide powder (Nu Zinc) with 1 litre of water (if not a stabilised product add 200mls of stabiliser and 800 ml water).
· Mix water and stabiliser first if using.
· Sprinkle powder on the water and leave to settle and wet.
· Stir to a creamy paste.
· Daily dosing 3.5 mls per 100kg liveweight
· 3-day dosing 13 mls per 100kgs liveweight.
· Weekly dosing 30 ml per 100 kgs liveweight
(dosing only when spore counts are high)
Crisis dosing (without previous long term dosing) gives less protection than long-term dosing and therefore requires higher dose rates to give adequate protection over short periods.
Stabilised Drenches: 5 ml/100kg Liveweight
Approximate dose volumes : Long Term Dosing
|Dose intervals (days)||1||3||7 (Dry cattle only)|
|Weight||Dose Volume (ml)|
|J x F||400||14||60||140|
|J x F||330||11.5||43||99|
|J x F||160||6||24||56|
Motor-driven Drenching Systems
Some motor driven drenching systems cannot be adjusted to the recommended dose volumes. Therefore the drench mixture must be adjusted so that the correct amount of zinc oxide is given.
Establish the drench volume per cow:
1. Deliver a set number of shots into a measuring jug.
2. Record the total volume.
3. Divide the total volume by the number of shots to get the shot volume,
e.g. if 10 shots gave 550mls = 550/10 = 55mls per shot.
4. Repeat at least once to confirm the result.
5. Determine the correct zinc oxide dose per cow from the table.
* Subtract 3mls from drench shot volume to compensate for the volume of zinc oxide e.g. 55ml – 3 = 52ml.
* Multiply volume and the zinc oxide dose rate by the number of cows e.g. 100 cows x (10g zinc oxide + 52mls water) = 1kg zinc oxide + 5.2 litres water (1kg + 5 litres rounded off).
* Multiply the daily mix by the number of days e.g. for 20 days = 20kg zinc oxide + 100 litres water.
|Jersey 350 kg||J x F 400 kg||Friesian 450 kg|
|Long term dosing (daily)||3 g per 100kg||10.5g||12g||13.5g|
|Crisis dosing (daily)||3.5 g per 100 kg||12.5g||14g||16g|
Zinc Sulphate in Drinking Water
There are four main methods of adding zinc to the drinking water of cattle.
1. Using an in-line dispenser to add a concentrated solution of zinc sulphate into the water reticulation system. Important points to remember:
· Set a level to which you will fill the reservoir containing concentrated zinc solution
· Adjust the dispenser or the reservoir volume to ensure that each day half to two thirds of its solution is injected into the water supply.
· Calculate the amount of zinc to be added each day (see table). Multiply the dose rate for each class of stock by the number then work out the daily requirement.
· At the same time each day add the total daily amount of Zinc Sulphate to the concentrate reservoir and then dilute with water to the FULL line. Stir to dissolve the zinc as you fill.
2. Adding Zinc Sulphate to a large tank (e.g. 22 000 litres, or 5 000 gals) which supplies the water reticulation system. The Zinc Sulphate is added to a large reservoir tank. The tank must contain at least 100 litres for every cow or cow equivalent. Remember the Zinc Sulphate should be added about the same time each day. Zinc Sulphate should be dissolved in water before adding to the tank.
3. Floating trough dispensers (Peta dispensers). Although not as reliable as the first two systems these still appear to give reasonable results and are ideal in situations with smaller numbers
4. Direct addition to the water trough – this will only cope with very small numbers of animals.
Note 1. The addition of Zinc Sulphate to the water supply is only suitable to long-term routine dosing – it is not suited to crisis dosing during danger periods. Make sure zinc is only distributed to stock. Household and shed water needs to be kept separate. Make sure that livestock do not have access to alternative fresh water during the period that zinc is being added. Addition to the water may be unreliable for treating animals not milking.
2. Mixing of other products in water (eg nutrimol) can reduce effectiveness by settling out the zinc in water lines. This may eventually block the lines and severe FE may result.
How to Start
Cows should be introduced to increasing zinc concentrations in water over a period of about 3-5 days.
Troughs on the reticulated system in paddocks that have not been grazed should be primed with zinc sulphate at the rate of 1 gram/litre (0.7 gram/litre monohydrate).
There are two forms of zinc sulphate available. Zinc sulphate heptahydrate is the material commonly available. Zinc sulphate monohydrate is a more concentrated form of zinc sulphate and is used at two-thirds the dose rates used for the heptahydrate.
Once calibrated, a volumetric measure is sufficiently accurate for regular use. Weigh out the required zinc sulphate into a plastic bucket. Level the surface and mark the height. Fill the bucket to this level each day.
CONCENTRATED ZINC SULPHATE SOLUTIONS ARE CAUSTIC.
AVOID DIRECT CONTACT AND WEAR PROTECTIVE GOGGLES
Requirements For Zinc Sulphate/Day In Drinking Water
|Class of Cattle||Heptahydrate
|Friesian cow||450 kg||36||25|
|F x J cows||400 kg||32||22|
|Jersey cow||350 kg||28||19|
|Friesian yearling||275 kg||22||15|
|Jersey yearling||215 kg||17||12|
|Friesian calf||190 kg||15||10|
Be sure to strictly follow the mixing instructions with all zinc products, in particular MONO-ZINC, which is always ADDED to WATER and not the water to the powder.
Other important factors for lameness are the size of the fat pad in the heel (this dissipates force onto the hoof walls, and is linked to BCS) and the thickness of the sole.
What can you do? The importance of track condition, careful use of the backing gate, treating lame cows promptly are still critical. In addition, maintaining BCS will help cushion their feet with the fat pad in the heel. And a new concept to me – Conditioning heifers’ feet by gradually introducing them to walking on concrete before calving.
There are several ways to accidentally poison stock with drench that you need to be aware of.
Pour-on is deadly if given by mouth. Overdosing by more than 50% is dangerous, especially with Levamisole or Selenium. There are no Abamectin (Ivomec-type) products licensed for oral use in cattle because of potential for overdosing. Never add drench to bulk tanks such as calf milk feeders as you will have no control over how much each animal drinks.
Always read directions and dose rates carefully, and if you have delegated drenching to other staff, make sure they fully understand your instructions, route of administration, and the dose rates.
Bloat Drench is extremely toxic to calves in it’s concentrate form. Never use old bloat drench drums as calf feeders.
Plants / Trees
– Oleander is extremely toxic, to stock and to people. In one case, 5 leaves killed 5 calves. Remove it with extreme care as scratches can also cause problems.
– Yew leaves, bark and seeds are all poisonous, and just as bad fresh or wilted. Do not throw trimmings into stock paddocks.
– Acorns are particularly poisonous when they are green (fallen during high winds). Calves suckling cows that have eaten acorns are most susceptible, followed by calves eating them, then adult animals.
– Rhododendron has been responsible for the death of several pet lambs, leading to great distress. Keep lambs out of the garden, and trimmings out of the paddock.
– Lily of the Valley contains digitalis glycosides, the same toxin found in foxglove. Once again, keep it away from stock.
There are plenty of other plants that can cause poisonings in stock, including Poa Aquatica (which has locally been known as Oreipunga disease due to its occurrence in this area), rhubarb, arum lily, macrocarpa (particularly after trimming or high winds), ragwort, tutu, hemlock, bracken fern, marijuana, and many others. Most will only be poisonous if eaten in large quantities but are better not to be eaten at all.
Rubbish / Dump Sites
Old car batteries and sheep dip have caused problems due to the lead and arsenic content. Beware the rubbish pile and inquisitive stock.
If you are concerned that your stock has eaten or been overdosed with any of the above, or you are unsure of how safe a product or plant matter is, please ring the clinic immediately on 0800 226 838 or (07) 827 7099 and ask to speak to a vet.
Coliform Mastitis 2016
We have seen quite a few coliform grades and coliform clinical mastitis cases this year. E.coli is a very common bug in faeces, and if the udders are contaminated then it can enter the tissue causing a mastitis.The very wet winter/spring we had will have increased the risk of dirty udders.
Generally a coliform grade is due to part of the plant not getting cleaned and sequestering some organic matter and hence allowing the bugs to proliferate, or due to dirty teats contaminating the milk lines. Coliform mastitis rarely causes grades, but there is often a common factor causing both. Thorough plant cleaning (check hot wash temperature, check acid/alkali wash, check all parts reached, check milk cooled quickly) and minimizing udder contamination are critical, but just washing udders may leave a bacterial soup. If they really need washing, they will need drying too with fresh paper towels (not the same dirty rag!) before putting cups on. Often a better, drier option is to trim the tails and address any dirty areas on the farm.
The classic coliform mastitis has a watery milk quality plus a very sick cow as the gram negative bacteria release toxins. We are treating these with anti-inflammatories, injectable antibiotics and fluids. If they do require antibiotics; milk culture and sensitivity have been showing frequent resistance to penicillin and cloxacillin, so other products need to be considered. However, we have also been seeing coliform mastitis that is not associated with a sick cow, and these often do not need treatment with antibiotics as the immune system will generally clear the brief infection.Milk samples are critical for confirming coliform mastitis, and antibiotic sensitivity profiles.
Mycoplasma update (May 2018)
We now have a positive farm confirmed in the Cambridge area, and several Waikato farms are under Movement Restriction and testing after NAIT movement tracing. The government will be announcing the national policy on Monday 28/5/18.
Commercial tests are now available; PCR tests for bull sheath scrapes, and for milk. These tests can yield both false positive or false negative results (it is a very frustrating disease!). Please contact the clinic if you would like to discuss these options.
Mycoplasma is spread primarily via direct contact from cow to cow (even over the fence) as the bacteria are found on the nose, respiratory tract, mammary gland, vagina and prepuce and transmitted in secretions such as milk, tears and semen.
Biosecurity is nonetheless vitally important to prevent transmission between farms on boots, equipment etc.
Remember disinfection is a 2 step process – first scrub to remove all the organic material, then disinfect!
Both testing and culling are now ongoing as well as continued surveillance. It is important that we maintain vigilance.
Keep an eye out for the signs:
· Swollen joints and lameness in cows
· Cows still quite bright
· Mastitis that does not respond to antibiotics
· Abortion and birth of weak calves
· Arthritis in calves
· Pneumonia in calves
· Middle ear infection in calves leading to a head tilt, and conjunctivitis
Mycoplasma are bacteria that do not have cell walls, so many antibiotics do not work, and they are difficult to culture in samples. The disease is common worldwide, but no evidence of its presence was found in NZ in 2007 when 244 bulk milk vats were tested. There is no human health risk or threat to trade.
Cambridge Veterinary Services offers both manual and ultrasound pregnancy testing services for cattle, and ultrasound pregnancy testing for alpacas. We have trained operators with proven experience and equipment. We can combine testing with reproductive analysis to ensure you know how your herd is performing.
Why Pregnancy Test?
Pregnancy testing of cattle is a very useful management tool. Different approaches will be required depending on the management situation and what you wish to know. It allows you to achieve many goals if done at the right time.
In situations of small numbers of cows, we will almost always use manual pregnancy testing, because it is faster, and because the ultrasound equipment is expensive and requires adequate restraint of the cow. Manual pregnancy testing also requires good facilities for the safety of people and cattle. A strong cow race is a minimum requirement, a headbale is better.
There is much debate on which method you should use. As far as accuracy is concerned they are both fairly even as long as the tester is experienced. They both have limitations in that they will only accurately date pregnancies between 6 and 16 weeks. After this time they both fail to see enough of the uterus to be very accurate for dating.
There is a very small risk of rectal rupture with scanning that does not exist with manual testing. Both can be done at the same speed if you are well organised. Cows will tend to strain more following manual testing. All cows scanned empty should be checked manually before being culled. We will do this as we scan the cows. Accurate recording of results is vital and empty cows should be permanently marked. Good tag numbers are essential.
The Best option
Alpacas can be ultrasound pregnancy tested from 4 weeks up to four months. Adequate facilities are required, talk to your vet.
Scanning can be done 6 weeks after mating in cattle. For manual and ultrasound testing we prefer to wait 8 weeks before confirming cows are empty.
One off whole herd testing
If whole herd testing is done eight weeks after the end of mating it is possible to remove all empty cows. This prevents the costly burden of carrying empty animals through the winter. This is especially so if you are looking for culls in a dry summer. It can be difficult to give accurate calving dates at this stage if mating started several months before as most of the pregnancies will be too advanced. This goes for scanning as well as manual palpation. We simply cannot size the pregnancy accurately after 16 weeks.
It is also a valuable exercise to pregnancy test heifers. This allows earlier heifers or those in calf to AB to be sorted from later or bull mated heifers. Late heifers may be culled early or selected for sale. Again timing is important to ensure you get the most out of it.
Finally any stock you buy should either be tested before purchase and certified in calf or tested once you get them home with right of return if empty. An empty cow isn’t worth much on the hooks compared with an incalf one in your herd! Make sure you check these cows.
Please note that research has shown a consistent occurrence of 2-5% foetal resorption before 12 weeks of pregnancy in cattle which is not related to pregnancy testing. After 12 weeks this drops to 0.5%
1-2% loss of pregnancy (slips) is accepted as normal in dairy herds.
The common and highly contagious disease infectious keratoconjunctivitis (pinkeye) can affect cattle at any age causing considerable pain and distress with significant economic losses due to reduced weight gain or weight loss.
How do cattle get infected?
A major predisposing factor in the development of pinkeye is damage to the cornea. This typically arises due to dust, long grass or plant pollens. The resulting damage then allows the bacteria, Moraxella Bovis to colonise the irritated area and start to multiply producing the characteristic signs of pink eye. Flies then feed on the secretions and spread disease from one animal to another.
What do we see?
Typically, affected animals develop a photophobia so they are squinting their eyes, the eyelids are often in spasm and there is a discharge staining the face. As the disease progresses, an ulcer starts to develop on the centre of the cornea surrounded by a ring of inflammation. The cornea develops oedema which gives it a blue appearance interfering with vision. In severe cases the cornea can perforate.
The cornerstone of treatment involves the administration of antibiotics either directly to the eye or locally. Antibiotic powders have been used widely in the past but have now fallen into disfavour due to the irritation caused by placing powders in the eye. Antibiotic eye ointment is a simple and effective means of treating mild to moderate cases. Early treatment will minimise the risk of permanent scarring to the cornea and reduced weight loss associated with pain. In more severe cases, the vet may opt for an ‘eye flap’ – temporary surgical closure of the eyelids in addition to medical treatment.
Prevention and Control
Control flies by using products that are licensed for fly control in cattle
Avoid grazing calves on long pasture
Remove affected animals from the main mob
Consider vaccination of healthy animals in known hot spots
Pinkeye in Sheep
Pinkeye is also a very common ailment afflicting sheep and goats however, unlike cattle, the pathogen implicated in disease is a Chlamydia species as opposed to Moraxella. Outbreaks in NZ are generally mild and occur annually in adult sheep during summer and autumn. As with the disease in cattle, infection is spread indirectly by dust, pollen in grass and flies which have been contaminated by the secretions of infected sheep. Handling of the face and head of sheep when drenching may be an important means of spread. Treatment, if required, generally involves the use of oxytetracycline sprays or ointments.
Theileria Associated Bovine Anaemia (TABA)
The recent NZ Vet Journal had a whole issue on the TABA epidemic. Here are a few highlights gleaned from the MPI and Massey authors:
Theileria orientalis was first reported in NZ in 1984, but the anaemia epidemic spanned from August 2012 to March 2014. In the first 18 months there were 496 case herds (reported to MPI); 79% were dairy and 21% beef.
Of 882 individual cases (submitted) 93% were positive for Theileria orientalis Ikeda. This is a protozoan parasite. There are 10 other types of T. orientalis, 3 of which have been found in NZ (chitose , buffeli and type 5). Chitose occasionally causes anaemia. Australia and Japan have also been significantly affected by Theileria orientalis, although it is found worldwide.
Theileria is carried and transmitted by the cattle tick Haemaphysalis longicornis. The larvae, nymphs and adults all feed on ruminants, but different individuals. The infection is not passed onto the tick eggs. A tick can pick up the parasite from the blood of an infected cow, and then pass it on to the next cow it feeds from. The tick-borne parasite is a protozoan, and the piroplasm form causes destruction of red blood cells, leading to anaemia. Animals can recover from infection, but the parasites may persist possibly for life; periods of stress such as calving can lead to a relapse. Disease is more frequently seen when naïve animals are introduced into an endemic area, or when infected animals are introduced to properties with ticks. The ticks are found throughout the North Island, plus Nelson and Golden Bay, and TABA has only occurred in tick areas.
Some interesting figures: Incidence risk 1%, cumulative mortality 0.23%, case fatality rate 17%.
It is believed the epidemic’s origin was the importation of infected cattle. There appear to be two scenarios of Theileria spreading. Firstly via cattle movements: farms that had Theileria were more likely to have brought cattle onto the farm, and from a greater distance. Trucking in infected cattle to a naive area would probably initiate each of these local outbreaks. Obviously the peak movement of 500,000 cattle happens on June 1st, leading to the mixing of infected and naïve cattle and ticks, and spread of the disease. Then a second localized spread via tick vectors: cases were seen in clusters within 20-30 days and up to 15-20km from a case farm. Infected tick nymphs can be carried to neighbouring properties by wildlife such as hares, horses, deer, dogs, goats and sheep. 100 ticks have been noted on the ears of a hare!
The time period from infection by tick bite to the parasite being found in the bloodstream is 10 days, and the number of bugs increase to 30-40 days, which is when the animal has the most severe anaemia and clinical signs. The peak of TABA in October 2013 therefore probably arose from infection soon after calving via the re-emergence of over-wintered nymphs. By the time you see a cow sick from it, she has been infectious to ticks for over a month already!
Beef calves were at greater risk of TABA than dairy calves, and calves were the most affected age group in Northland. This is probably because beef calves are born later (coinciding with the peak questing period of overwintered nymphs), dairy calves are housed for the first few weeks, and tick density is higher in Northland with earlier resumption of tick activity. Data from Africa suggests that as an area becomes endemically stable, the incidence of obvious disease falls and is often restricted to young animals; this may explain why there was lower risk of disease in Northland. In contrast, the Waikato bore the brunt of TABA with adult dairy cattle.
The prediction is that some areas will reach endemic stability (with clinical disease not being seen much as ticks and theileria are a constant factor), but that epidemics (outbreaks of disease) may continue in areas of marginal tick habitat. Practical treatments still focus around pasture management, tick control, animal husbandry (minimizing stress), supportive therapy and, if needed, blood transfusion. Buparvaquone is effective but the with-holding is too long to be practical. Some research work for a potential vaccine was being done in Japan.
UPDATE ON ANIMAL WELFARE REGULATIONS
Cattle and sheep cannot be transported:
- With an injured udder or mastitis,
- in late pregnancy (and give birth within 24 hrs),
- with eye cancer that is >2cm or bleeding, or if they are lame
- With ingrown horns or horns that may cause injury
SHEEP AND BEEF
- Mulesing sheep is prohibited
- Local anaesthetic must be used if castrating with a high tension band (not a rubber ring) or at over 6 months of age
- Do not allow horns to become ingrown
- Do not allow horns to become ingrown
- Inserting objects into cows for milk let-down is prohibited
- Removing any part of a cow’s tail is now prohibited
- Do not use a goad to strike or prod livestock in sensitive areas
- Local anaesthetic must be used for disbudding or dehorning
- Shelter – make sure your animals have appropriate shelter (dry, shaded, ventilated, clean, big enough, food and water nearby)
- Dogs on the backs of utes must be secured so they cannot fall off
- It is best not to tether your goat for long periods, but collars and tethers must fit so the animal can eat, drink, breathe and pant and does not cause injury.
- Equipment must fit, be clean, and not cause injury
- Transporting calves – if the ute / deck is higher than 90cm, loading facilities are required.
As a profession we are passionate about both animal welfare, and farmer welfare!
- Bobby calves must be fed, kept in suitable shelter, and handled with due care. As of next year, a ramp must be available for them to walk up to the truck.
- Euthanasia by blunt force trauma is not allowed. Personnel must be trained and competent to use a firearm or captive bolt.
- Hip lifters are to be removed if the cow cannot promptly support her own weight.
- Cows must not be transported where her weight is taken entirely by the hip clamps/vehicle.
- Cows supported in a sling must be able to breathe freely, not suffer unnecessary discomfort, and be lowered if they are not supporting their own weight within one hour.
- If they are still recumbent after 48 hours, a vet examination is recommended – we can check for dislocated hips or other diagnosis, give a prognosis, or feedback on welfare.
- Animals must be fit for Transport. Calves must be at least 4 days old, healthy, able to stand with a dry navel and fed within 2 hours. Adult cattle must be bearing weight evenly on all 4 legs; if they are lame or have any health issue, a vet may issue a certificate only if they meet certain criteria.
- Milk letdown must not be stimulated by insertion of water or air into the vagina.
- It is best practice to have an Animal Health Plan written in consultation with your vet. This provides an opportunity to go over husbandry skills, to plan ahead, and formalize decision trees for mastitis, lameness, calvings and recumbent cows for example.
such as always using pain relief for disbudding/dehorning.
BVD infections can be disruptive and costly. Finding and controlling PI (Persistently Infected) stock on your farm is an essential start.