- Feeding of Pet/Fostered Lambs
- Facial Eczema
- Fly Strike
- Ryegrass Staggers
- Livestock Poisoning
- Mating Vax
- Sheep Mating
- Worms
Day 1:
The lamb requires 5-6 feeds of high quality colostrum spaced evenly throughout the day. Colostrum is absolutely critical for the lamb to establish an active immune system and to provide antibodies that will help the lamb to fight infection and prevent scours. The aim is to feed about 125ml per feed for a 4kg lamb.
Day 2-4:
Big robust lambs that have adapted well to the bottle can have the number of feeds reduced to 3-4/day but the volume increased. Aim to feed 200-300mls per feed. Do not be tempted to overfeed! It is best to keep the lambs a little hungry especially in the first few days. Overfeeding can lead to scours or bloating.
Day 5 onwards:
Transition lambs onto cold, yoghurtised milk. The most common cause of pet lamb deaths is abomasal bloat. THIS IS REALLY COMMON! A bacteria called Sarcinia lives in the abomasum and helps to digest the lactose in milk. When Sarcinia starts to proliferate it produces a large volume of gas, which if not removed quickly by the lamb, can result in abomasal bloat and death of the lamb. Rearing lambs on cold yoghurtised milk will virtually eliminate this issue.
To Make Yoghurtised Milk
- Place 3L of warm water (40C) in a 9L bucket (ensure the bucket is twice the volume to your milk or you may have a mess to clean up)
- Add 1 kg of Anlamb powder and mix with a stick blender
- Add a 200ml Easiyo Satchet to the water and mix again
- Leave in the hot water cupboard to thicken (8-12hrs)
The mix varies from a bubbly thickshake to crusty cream cheese sitting on top of a clear liquid, to thick commercial yoghurt - Top up with cold water to the 8L mark on the bucket
- Remove 200ml of this liquid for use as the started for the next batch
- When it’s time to feed the lamb, whisk the mix well and decant what you need and feed cold
- Introduce the yoghurt with a gradual transition from warm to cold feeding
- You can change the bucket every so often for a clean one if you prefer
- You may need to occasionally ‘recharge’ the mixture with extra yoghurt if it gets too thin or seems to not be fermenting well.
Lamb Scours
The vast majority of scours in lambs is nutritional/osmotic rather than infectious and are generally easily fixed:
- At the first sign of a mild scour with the lamb still bright and drinking
- Increase the concentration of the milk replacer being fed by around 20-25%
- Cut the water down but use the same amount of powder
- Also reduce the volume fed for two or three feeds by 50ml
- This will frequently stop the scour, but make sure the lamb has fresh water available and watch for constipation, this can happen quite easily.When the scour stops, transition back to normal volume and concentration.
- If the above approach doesn’t work or the lamb is dull or inappetant, you will need to move onto the electrolyte therapy.
- Please talk to your vet. When the milk is reintroduced, use the reduced volume/increased concentration approach as above.
Facial eczema (FE) is a disease of sheep, cattle, deer and alpacas. It can cause death, photosensitization and lowered production as a result of liver injury, and is mainly seen during periods of warm humid weather between January and May.
The pasture fungus Pithomyces charatarum multiplies and produces spores, which contain the toxin Sporidesmin. Sporidesmin causes injury to the liver. The bile ducts become thickened and may be completely blocked. The damaged liver cannot rid the body of wastes and a breakdownproduct of chlorophyll accumulates in the tissues and causes sensitivity to sunlight.
Sunlight causes immediate and severe skin inflammation to exposed parts of the body.The symptoms of FE therefore can vary from severe photo-sensitisation and in some cases death to sub-clinical effects on the production of meat, wool and milk. In any FE outbreak, many animals with liver damage show no clinical signs – but they suffer from subclinical FE.
Photosensitisation tends to occur about 2 weeks after exposure to spores and is characterised by irritation, reddening and oedema (puffiness) of exposed hairless or non-pigmented skin. This is followed by serum ooze and ultimately large sheets of skin may slough. Many animals affected by FE do not show outward signs; in fact only about 20% of animals with FE show skin signs. There will however, be some degree of liver damage and overall wellbeing will be compromised.
For rapid growth and spore formation the fungus needs warm, moist conditions common during the autumn. 4-5mm of rain or even heavy dews in conjunction with 2-4 nights when grass minimum temperatures remain above 12 degrees Celsius are sufficient to initiate rapid increases in spore numbers. Spore counts rise even more rapidly when minimum temperature of the grass is high (15-16⁰C) and associated with high humidity and/or light rain. Generally it takes two or three such “danger” periods before spore numbers reach dangerous levels, each spore rise providing the base for the next increase in spore numbers. However prolonged periods of warm, humid weather early in the season can accelerate the onset of toxic pastures.
Predicting and identifying danger periods by monitoring spore countsThe control of FE includes:
Spraying pastures with fungicide to prevent spore growth
Administering zinc
Cambridge Veterinary Services provides a daily spore count service through the eczema season. Grass samples are submitted to the clinic and results are reported to the owner the same day. The data is then collated as part of the ongoing monitoring service that we provide and is updated frequently on our website. Spore count information can be obtained by calling the clinic or from the website / Facebook page.
Prevention Options
Zinc can be administered in a number of ways:
Zinc sulphate through the water trough
60% effective
Not very palatable – flavourants required
Needs to be gradually introduced over time
No access to alternative water sources
Not suitable for providing protection in a “crisis” period
Zinc oxide oral drench
75-80% effective
Zinc bullet
90% effective
Great for young stock
Slow release over a period of time
Faceguard or Time Capsule
Repeat administration required – usually 2-3 times in Waikato
Pasture Spraying
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 new “Mycotak /Mycowet” system is also possible. This is the best option for owners of Alpacas. Please enquire about these
Timecapsules
Faceguard Vs. Time Capsule
Both zinc bullets are inserted orally via a gun and sit within the rumen releasing a continuous, controlled amount of zinc over a period of time. It is highly effective and safe in most situations.
Time Capsules
Boluses contain compressed zinc oxide surrounded by a green shell of beeswax. The products come in a number of sizes according to the weight of the animal and requires repeat application every 4-5 weeks in cattle (4 weeks when counts are high) and will provide protection for six weeks in sheep and lambs.
The disadvantage with Time Capsules as you are probably aware, is the products fragility. If the green beeswax outing coating is damaged in any way the product cannot be used as there is a risk of zinc poisoning, which can be fatal.
Faceguard boluses contain compressed zinc metal. Faceguard
In contrast to Time Capsules’, Faceguard bullets are extremely robust and can handle being dropped. They are less likely to cause toxicity issues compared to the Time Capsule (whose outer wax coating can be damaged by teeth at insertion which means it is digested faster and not provide protection for 4 weeks).
The faceguard bullet comes in only one size so if the animal is bigger then you adjust the number of bullets given. A special gun is used (different to the Time Capsule gun) and is loaded with more bullets for heavier calves rather than having to have several different sized heads with the Time Capsule. A maximum of 5 bullets can be inserted into the gun. A single treatment will last 6 weeks (as opposed to 4 weeks) and re-treatment can extend this out to either 10 or 12 weeks.
Cattle Zinc Drenching
Long Term Dosing Stabilised Drench eg Global Supa-Zinc
Mix 1 kg 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 100 kgs live weight
• 3-day dosing 13 mls per 100 kgs live weight.
• Weekly dosing 30 ml per 100 kgs live weight
Crisis dosing (only when spore counts are high), without previous long term dosing, gives less protection than long-term dosing and requires higher dose rates for protection over short periods. Stabilized drenches: 5ml/100kg live weight
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.
There are two forms of zinc sulphate available; heptahydrate is commonly available, monohydrate is more concentrated and is used at 2/3 the dose of heptahydrate.
Troughs on the reticulated system in paddocks that have not been grazed should be primed with zinc sulphate at the rate of 1g/L (0.7g monohydrate per litre).
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.
Be sure to follow the mixing instructions with all zinc products, in particular adding mono-zinc to water not the water to the powder.
Take home message
FE is a debilitating disease of livestock that can be largely prevented through knowledge of the disease and prophylactic administration of zinc at strategic times of the year. Start monitoring spore counts in December and institute preventative measures when conditions favour the proliferation of spores. If in doubt, be sure to contact your veterinarian to discuss the right approach for your animals.
DEER
Red deer are more susceptible to FE than cattle. Fallow deer are more susceptible than sheep so they need more protection than Reds.
Prevention options include:
Spraying pastures with fungicide – Regular spraying with fungicides provides the most appropriate control method for preventing FE in deer. Start the spraying programme early while spore counts are low.
Zinc – the effectiveness and safety of zinc as a prevention has not been researched. If used, dose rates as for sheep (Fallow deer) and cattle (Red deer) should be followed. Because of low water intake, zinc in drinking water is not highly effective but will help in some situations.
Provide supplementary feed – such as hay, silage, meal or crop
SHEEP
Grazing Management
Planned grazing can substantially reduce the risk of FE in hill country. Good planning is essential and it must start months in advance.
Identify the safe areas on your farm and aim to have a feed bank on these areas for the FE season. The best way to identify the safer areas on your farm is by regular spore counting over several years – but in the meantime the shady south facing faces are generally safest.
The spores are concentrated in the litter at the base of the pasture so the harder the sheep
graze the greater the risk of FE.
Try to minimise the number of young stock retained to late summer and autumn.
Breeding for Resistance in Rams
Tolerance to FE is strongly inherited so sourcing rams tolerant to FE will reduce the susceptibility of their offspring to FE
Sheep can be dosed at twice weekly, weekly or fortnightly intervals with Zinc Oxide. However the longer the interval, the lower the level of protection. Salmonellosis has been
associated with fortnightly dosing so if this is a potential problem shorter intervals are recommended. Watch for diseases like pink eye and pneumonia, which may also develop due to frequent yarding.
RECOMMENDED DOSE RATES:
Stabilised drench – 0.5ml/1 0kg LW x interval (days) (recipes for mixing these drenches are in the cattle section).
GOATS
Goats are generally more resistant than sheep and their browsing habits make them less prone to ingesting spores. Milking goats are probably at greatest risk. Prevention is best achieved by never making stock graze into the base level of pastures. The fungus grows on the litter at the base of the pasture and the spores are concentrated there. Other options include:
Spray pasture with fungicide
Provide supplementary feed (crops, fodder, hay, silage)
Zinc prevention – in highly toxic conditions use zinc oxide as for sheep
Flystrike is estimated to cost the New Zealand sheep industry about $37 million a year, with those losses coming from deaths, treatment costs, and loss of meat and wool production. Even relatively minor strikes can result in marked appetite loss and subsequent losses of weight with prolonged recovery times.
* at 3ltr applied washFour species of blowfly are recorded as causing strikes on sheep in New Zealand, with the Australian green blowfly [Lucilia cuprina] and the European green blowfly [Lucilia sericata] recognized as the most important primary strike flies.
Prevention of flystrike is largely reliant on the application of insecticides by a variety of means [saturation dipping, jetting, low volume pour-ons or spray-on] to the fleece of ‘at risk’ animals, along with good animal husbandry for effective worm control and to prevent faecal soiling, and crutching and shearing at appropriate times. The preventative chemicals most commonly used belong to the broad insect growth regulator [IGR] group of compounds.The IGR’s fall into two distinct chemical classes;
1.Triazine/pyrimidine derivatives such as cyromazine [Vetrazin] and dicyclanil [CLiK and CLiKZiN]
2. Benzoyl phenyl urea [BPU] compounds represented by diflubenzuron and triflumuronLucilia spp blowflies have demonstrated a remarkable ability to develop resistance to various chemicals used to control or prevent flystrike, with resistance first manifested as a shorter than expected period of protection in spite of proper application and dosage. Strains of Lucilia spp. resistant to diazinon an organophoshate, have been recorded throughout New Zealand and recent surveys have suggested that there may be widespread resistance to BPUs in the Waikato.Minimizing the losses caused by flystrike requires a planned preventative approach using effective products. A preventative approach means treatments are applied before expected fly activity rather than waiting until animals get struck. Resistance management needs to be factored in when planning flystrike prevention programmes, alongside other key factors such as rainfall, class of sheep, shearing, docking and weaning dates, product application method and previous fly challenge. If you have any doubts about the effectiveness of your current flystrike prevention programme please give us a call.See individual pack details for full instructions on how to get the best out of your choice
of product.
ataxia, falling over, and a high-stepping gait. The clinical signs are an effect of a depolarising blockade of the purkinje neurons in the cerebellum.
Potassium Bromide (KBr) has been used for ages to help treat seizures. It has the opposite effect to lolitrem B (hyperpolarizing the cerebellar nerve cells), so a group in Australia trialled the treatment of Ryegrass Staggers/ Toxicosis in lambs with a drench of potassium bromide.
Various groups of lambs were fed either Lucerne chaff or ryegrass seed containing lolitremB, and then some were treated with Potassium Bromide either as a single dose or as a daily drench.
Those lambs which were fed ryegrass seed with loitrem B and developed moderate tremor and gait abnormalities who were subsequently given a single drench of KBr had a reduced likelihood of falling and a better gait. They also had lower muscle voltage, suggesting reduced tremor. It may also reduce stress levels (measured by cortisol concentration).
In the future, this could be a useful treatment to help farmers move affected stock, to perform husbandry procedures on them, or to treat recumbent animals. However, the dose rate and safety of the product has not been established for ruminants, so further studies will be needed.
So for now, it is best to identify at-risk paddocks and avoid grazing them with susceptible stock (especially calves). They show signs particularly when grazing seedy grass or grazing really low. New varieties of ryegrass are available for re-drilling paddocks which do not contain the endophyte.
If you do see animals showing signs of ryegrass staggers, it is best to minimize stress and droving. Monitor them for accidents (e.g. getting cast or stuck), and be slow and gentle with them. Delay yarding if possible.
Drench
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.
Other plants
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.
Androvax is a vaccine that increases fecundity in breeding ewes, increasing lambing percentage by an average 20%. It contains an androstenedione-protein complex which raises antibody levels, causing a change in hormone production which temporarily blocks the release of eggs from the ovaries. More eggs mature and when antibody levels fall these extra eggs are released, thus increasing the number of lambs born.
In the first year two doses are administered. The first dose is given 8 – 10 weeks before ewes are mated and the second dose at 4 – 6 weeks prior to mating. In subsequent years, previously vaccinated ewes only need a single booster injection 4 – 6 weeks prior to mating.
Toxovax
Toxoplasmosis never goes away and has been shown to be present on every sheep farm in New Zealand. One shot of
Toxovax gives your ewes a lifetime of protection against the devastating abortion storms Toxoplasmosis can cause.
Vaccination can increase lamb numbers by an average of 3% as well as decreasing the number of dry ewes by 14% on average.
Ewe hoggets and two tooths are most at risk, but any susceptible ewe that contracts Toxoplasmosis during pregnancy is at risk. Infection causes:
¨ At early gestation – embryonic loss or reabsorption
¨ Mid gestation – fetal death, mummification and abortion
¨ Late gestation – birth of weak, non-viable lambs
The life cycle of Toxoplasmosis involves wild birds and rodents who have cysts in their muscle and are then eaten by cats. Cats then pass out the infective stage of the life cycle directly onto pasture or hay via faeces. Sheep grazing on this contaminated pasture or hay can pick up the disease, and if this occurs for the first time during pregnancy, abortions can occur. Often the farmer sees a reduced scanning percentage and a lot of late or dry ewes. Abortions are not always seen.
Toxovax is a live vaccine, has a short shelf life and is made to order. Please order your Toxovax from us at least four weeks before you need to use it, which should be at least 4 weeks before mating, to ensure supply.
Campyvax – requires a booster pre-tupping and a sensitizer 4-8 weeks earlier for ewe lambs.
Vaccinating with Campyvax® improves lambing performance and prevention of Campylobacter abortions. Flocks that are vaccinated have lambing percentages on average 9% higher than flocks that are not. Vaccination should happen 4-8 weeks prior to mating. Hoggets need a sensitizer dose 4 weeks before this shot (ie 8-12 weeks before mating).
- Campylobacter is present on 88% of New Zealand farms.
- Maiden Ewes hoggets or two tooths are most at risk but mixed age ewes who have not been previously exposed (up to 50%) are still at risk too.
- It is the most common infectious agent causing abortion on New Zealand farms, with 60% of sheep abortions diagnosed attributed to Campylobacter.
- Occurs when susceptible animals ingest contaminated feed or water, or by direct contact with infected fetuses or fetal membranes. Scavenging birds such as the Black Backed Gull may spread the disease between paddocks and even farms.
- After infection, the organism is present in discharges for up to six weeks, with some ewes becoming longer-term carriers.
- Infection can persist for a number of years in carrier sheep without overt signs of disease.
- Signs are not just aborted lambs, there may be reduced scanning and lambing percentages too.
I know it seems an age away, but far too quickly the rams will be joining the ewes. I was reminded of this last week when asked to vasectomize some rams to make them teasers! This system works very well to compact mating; the presence of (vasectomized) rams prior to the mating season brings the ewes into heat for the real rams! It is a relatively straightforward veterinary surgery, but needs to be done a month or two before their introduction to ensure they are not fertile. Other things to consider ahead of time are the 2 major causes of abortion, for which highly effective vaccines are available.
WORMWISE – sheep, goats and calves
There is a LOT of worm resistance to drenches reported by the labs, which is defined as a reduction of <90%in faecal egg count after drenching. In fact resistance has already developed to one of the “new” sheep drenches recently developed.
The Wormwise website gives some great advice for reducing the risk.
Faecal egg counts are a great way of seeing if animals actually need a drench (why waste time and money?), and if a drench has done the job (7-10 days after drenching). Simply drop off some samples to our clinic – we can give you some plastic pots.
How often do you need to drench? It depends on the pasture burden, stocking density, species grazing, weather impact on worm lifecycle, drench used…
Paddocks that just graze youngstock will develop a higher worm burden.
Co-grazing different species, or rotating youngstock with adult cattle, will reduce the worm burden.
Warm, wet weather is ideal for worms and quickens their lifecycle – some species 14 days! Does this sound familiar in the Waikato?
Oral drenches tend to have no residual activity whereas pour-on and injectable generally last a month. But oral drenches seem to be more effective in youngstock.
Check the weight of some animals, the recommended dose rate, the dose actually delivered by the gun into a measuring jug, and that the product is not out of date!
Combination drenches will reduce the risk of resistance.
Levamisole (clear drench) is still the best for cooperia ……
Refugia allows the dilution of resistant worm eggs with “normal” eggs from undrenched animals, and the resistance genes generally have an energy cost which makes them less competitive. In practice, this means not drenching the best 10% of the mob, or similar strategy.
BARBER’S POLE!
We have diagnosed some Barber’s pole worms in sheep December 2024. The warm weather with rain has been ideal for worms, so you may need to consider drenching your lambs, or even better dropping a faecal sample into the clinic for a worm egg count.
Barber’s pole (Haemonchus contortus, has a red strip curling around it) causes anaemia in sheep, which can result in slow lambs with pale gums and eyes, or sudden death. The lifecycle of this helminth can be as short as 2 weeks, so you may want to consider using a drench with extended activity against Haemonchus, such as Cydectin S or Clomax, but be aware of the latter’s long with-holding period.
Goats do not seem to have developed much immunity to worms compared to other ruminants, so even adults often need worming over summer. We recommend increasing the dose to about 50% above what sheep are advised.
Goats
Prevention is best achieved by never making stock graze into the base level of pastures. The fungus grows on the litter at the base of the pasture and the spores are concentrated there.
Other options include:
· Spray pastures with fungicide.
· Use a suitable zinc prevention method. In highly toxic conditions use zinc oxide prevention as for sheep.
· Provide supplementary feed (crops, fodder, hay or silage) to reduce grazing pressure on toxic pastures.
The nature of the mastitis seemed to be contagious, so control measures to reduce prevalence as well as transmission may be effective in controlling IMI: teat spraying, optimal milking machine function, and milker hygiene.
IMI was found to increase gland SCC, but only affected Bulk Tank SCC in early lactation, as goats’ SCC increases later in lactation anyway. Stress can also cause a rise in SCC.