CALF SCOURS: THE PROBLEM
Calf diarrhoea (calf scours) remains one of the most important challenges faced by many dairy farmers in Australia and is the cause of enormous economic loss. Incidence rates vary greatly, with rates of 15-30% or higher, not uncommon. Mortality rates often range from 3-5% or higher, even on well managed dairy farms.
Many factors can contribute to a calf scours problem – poor hygiene, inadequate colostrum management and the persistence of high levels of infectious agents in the environment. The most important pathogens involved are:
- .Eschericia coli K99 (E.coli K99)
- .Cryptosporidium parvum
- .Salmonella spp.
- .Clostridium perfringens.
Whilst calf scours may occur at any time, it is generally within the first 3-4 weeks of life that calves are most susceptible to contracting these debilitating and potentially fatal infections. As well as losses due to calf deaths, it has been identified that many calves that recover from diarrhoea experience depressed growth rates due to intestinal damage.
Calf scours can deliver long term financial and animal health impacts on your operation – going beyond the obvious treatment and disease management issues.
DIAGNOSIS With the onset of diarrhoea comes rapid dehydration and debilitation. Rehydration, along with antibiotics/antiprotozoals where appropriate, is generally the cornerstone of treatment of affected calves.
In suspected infectious calf scours, it is important to accurately diagnose the cause. The Rainbow 6 test kit is a calf side test that can be easily used on farm to diagnose Rotavirus, Coronavirus, E.coli, Cryprosporidium parvum and Clostridium perfringens.
Benefits of the Rainbow 6 test kit: • Identify major scours pathogens for more appropriate treatment and prevention strategies. • Rapid on farm diagnosis, with results available in 10-15 minutes. • Available from your local veterinarian.
TREATMENT AND PREVENTION
- REHYDRATION – Rehydration of the calf is essential. Dehydration kills calves as they stop suckling (due to weakness and acidosis etc.). There are a number of oral rehydration treatments available, talk to advisors about the most appropriate one to use. Veterinarians will sometimes use intravenous antibiotics in severely dehydrated calves, or to address acid/base imbalances. Don’t under-estimate how much fluid a dehydrated calf requires (a healthy calf needs approx. 10% bodyweight of fluid a day, depending on the environmental temperature, just for maintenance).
- DIAGNOSIS – It is important to diagnose the cause of a calf scours outbreak. There is not one single cause of calf scours, multiple viruses, bacteria and protozoa can be involved in calf scours, often simultaneously. Calf scours results from an interaction between calf management, hygiene, poor immunity and various infectious organisms. It is important to find out the cause of an outbreak so that an effective preventative program can be put in place.
- TREATMENT – the most important treatment is rehydration. Once a diagnosis is reached oral or injectable antibiotics may be required for treatment under the advice of your veterinarian. When using antibiotics always consider the withholding periods and keep treated calves separate from untreated calves.
- HYGIENE/QUARANTINE – vital in management of an outbreak or in prevention of scours.
- Calf shed – adequate clean bedding, regular removal of manure, cleaning of rails/gates, regular changing of gloves when handling scouring calves, cleaning and disinfection of feeding equipment. Quarantine area for new calves and hospital area with individual pens.
- Calving area – consider changing the calving pad or paddock if an outbreak occurs. Contamination may build up late in calving – resulting in an increased number of scouring calves late in calving.
- COLOSTRUM MANAGEMENT – the concentration of antibodies in colostrum is at its highest immediately after calving and, due to volume increase, declines from 12 hours after calving. • Timing – all calves should receive colostrum within 12 hours of birth – by oesophageal tube if necessary. • Quantity – a calf should receive 10% of their bodyweight (i.e. 4 litres for a 40 kg calf) of good quality colostrum in the first 12 hours after birth and a similar quantity in the next 12 hours. A calf should not receive more than 5% bodyweight in colostrum at any one feed and feeds should be spaced by at least 2 hours. • Quality – colostrum quality should be measured with a Brix refractometer prior to feeding, to ensure the colostrum being fed has an adequate concentration of antibodies. Good quality colostrum will have a reading of 22 % or higher on the Brix scale. Pooling colostrum is not recommended unless it is all of good quality. Colostrum should be stored at 4°C to avoid overgrowth of harmful pathogens. Freshly harvested colostrum can be stored in the fridge for a maximum of 2 days.
- VACCINATION PROGRAMMES – the aim is to vaccinate cows in late pregnancy so as the colostrum has a high level of specific antibodies, to provide the young calf with direct protection against calf scours.
- Rotavec Corona – vaccination against Rotavirus, Coronavirus, E.coli and Clostridium perfringens.
- Bovilis S – vaccination to aid in the control of Salmonellosis caused by Salmonella typhimurium and Salmonella dublin.
These vaccines protect the calf by increasing antibodies in colostrum:
- Antibody absorption declines rapidly after 12 hours of life so it is vital that newborn calves receive an adequate volume of good quality colostrum within 12 hours of being born (10% of bodyweight in good quality colostrum is required within this time).
- During a disease outbreak or in high risk situations, it may be necessary to continue colostrum feeding for up to 5 days to provide some local protection in the gut.
- Cow health and nutrition is important to achieve good quality colostrum.
- Heifer colostrum is sometimes of poor quality – many dairy producers pool good quality colostrum from older cows to feed calves from first calving heifers
Pinkeye is a highly infectious bacterial disease of cattle that results in eye inflammation, ulceration, corneal scarring and possible blindness. Coopers Piliguard is the only vaccine available in Australia for the prevention of pinkeye. The vaccine works as an aid in the control of pinkeye caused by the bacteria Moraxella bovis.
The Disease: In Australia the most commonly isolated bacteria from cattle with pinkeye is Moraxella bovis.
Moraxella bovis is carried in the eyes of adult cattle – these cattle are not usually affected by pinkeye but they provide a source of bacteria to infect younger, naïve stock. Flies transmit the bacteria between cattle, and spread can also be by physical contact between cattle, as the bacteria will survive in eye and nasal discharges.
Once an animal is exposed to M. bovis the bacteria attaches to the cornea, reproduces and produces toxins which damage the surface of the eye, eroding the cornea and causing severe inflammation.
Pinkeye – Predisposing Factors:
Any factors that cause damage to the eye, or increase the exposure of animals to the bacteria, have the potential to increase the incidence of pinkeye in a herd. These factors include:
- Flies – spread bacteria
- Age – pinkeye is more common in younger cattle (due to a lack of immunity and also because they are more likely to be in close contact).
- Dust – irritates eyes, increases tear production and assists spread
- Ultraviolet light – sensitises eyes
- Long grass and grass seed – damages eyes
- Pigmentation – pinkeye is generally more common in non-pigmented eyes
- Cattle type – more common in Bos taurus than Bos indicus cattle
- Intense husbandry (eg drought feeding, yard weaning, dairies) – can increase incidence
- Immune status – cattle in poor body condition tend to be less able to mount an immune response
Costs of pinkeye:
A recent Meat and Livestock Australia (MLA) report estimates that the disease costs Australian beef farmers $23.5 million annually in lost production and treatment costs.
A range of studies have highlighted a number of direct and hidden costs caused by pinkeye:
Production losses, e.g. lower weight gain (up to 10%) and lower milk production
Cost of treatment – drugs, labour, vet fees
Loss of carcass value and access to some markets, delayed sale
Loss of genetic material due to culling of affected animals
Stud animals – reduced sale price/removal from sale
Traditional treatment methods can increase
Increased death by misadventure
Negative effects on fertility
Discomfort and blindness
Animal welfare concerns
Prevention of Pinkeye:
- Vaccinate animals with Piliguard 3-6 weeks before the onset of the pinkeye season (Piliguard can be used on calves from 1 week of age).
- Use other management tools to control the spread of pinkeye:
- Fly control – Integrated Pest Management incorporating the use of Coopers Easy-Dose at the onset of the fly season
- Segregate and treat clinical cases early – this will decrease the number of infective bacteria in the herd and limit spread
- Avoid yarding animals in dry, dusty conditions so as to minimise eye irritation and transmission to susceptible animals
Pre-vaccination with Coopers BOVILIS MH+IBR
This spring, feedlots in your area continue to pay a premium of up to $15 a head for cattle vaccinated with Bovilis® MH+iBR prior to feedlot entry. This is because cattle pre-vaccinated with Bovilis MH+iBR are proven to perform better 1.
In order to highlight this to cattle producers, Coopers® are running an advertising campaign in target regions that supply cattle to major feedlots. The campaign will include radio, direct mail and on-farm activities, all directing producers to source their vaccine from local stockists.
Cattle producers have told us that one of the main reasons why they have not vaccinated previously was that they were not sure which stores held Bovilis MH+iBR in stock. That is where we can help make your store stand out from the crowd.
When you commit to stocking BOVILIS MH+IBR in your fridge
- Your store will be added to our website as a pre-vacc supplier
- Coopers will detail to feedlot buyers outlets that hold vaccine in stock
- Coopers can work with you to develop local client ‘pre-vacc events’
- Coopers will help ‘pre-vacc train’ your staff
To find out more about how we can help drive customers to your store contact your local Coopers representative today.
PRE-FEEDLOT BRD VACCINATION WITH BOVILIS MH+IBR IS NOW MORE FLEXIBLE.
Now 14-180 days between doses allowing vaccination at weaning.
Bovine Respiratory Disease (BRD) causes between 50% and 90%1 of sickness and death in Australian feedlots, and it’s estimated to cost the Beef Industry $60 million annually2. BRD is a complex disease involving many contributing factors that, if combined, compromise the respiratory defences of affected cattle, allowing infection to establish in the lungs and produce severe, often fatal, pneumonia. Contributing factors include stressors such as transport, dietary changes, feedlot induction, pen competition and mixing of cattle from different sources.
Over the last two years major Australian feedlots have started paying a premium for cattle pre-vaccinated with Bovilis MH + IBR from Coopers Animal Health. Bovilis MH + IBR is a combination vaccine given subcutaneously that helps to control bacterial and viral causes of BRD. Controlling BRD has been proven to help cattle perform better in the feedlot. Bovilis MH + IBR now has a flexible inter-vaccination interval (the time between the first and the second dose) of 14 to 180 days. This recently achieved new label claim has been possible due to scientific data generated in Australian cattle and is great news for the Australian Beef Industry. Cattle producers supplying cattle to feedlots can now pre-vaccinate at the same time as other normal management practices at weaning and reap the rewards at sale time. Feedlots can now feel safe in the knowledge that their traditional suppliers will have plenty of time to vaccinate pre sale. Resellers can confidently stock Bovilis MH+IBR as it becomes part of standard cattle management rather than a last minute rush order.
Paul Speers, Marketing Manager for Coopers Animal Health says “Over the last couple of years, sales of Bovilis MH+IBR have increased by over 50% as feedlots and Backgrounders recognised the benefits the vaccine provides in helping to control BRD, thereby reducing morbidity and mortality. The main barrier to use however has been the short window available to apply the vaccine prior to sale of the animal. By providing flexibility in the interval between doses we’ve made it possible for cattle producers to pre-vaccinate their cattle at a time that fits with other farm activities. While we have been working hard with our pre-vaccination partners to ensure the vaccine is available to producers, this extension reinforces the work that we have been doing behind the scenes to make it easier to use this vaccine.” –
HIT LICE EARLY AND HIT THEM ONCE
Stampede is the only cattle lousicide to contain Insect Growth Regulator (IGR) technology. Stampede is a pour-on formulation containing 20 g/L diflubenzuron, an Insect Growth Regulator (IGR) that prevents lice nymphs from developing, due to its action against the enzyme chitin synthetase.
Stampede stays active on the animals for months after treatment reducing the likelihood of retreatment being required during the season.
Treat cattle for lice around the first cold snap in autumn, when eggs are likely to be hatching. Immature lice larvae present at application and those which hatch from eggs post application are prevented from developing to adults, thus breaking the breeding cycle.
Stampede produces a rapid decline in lice numbers over several weeks – it inhibits the development of nymphs and adult lice will take some weeks to die out. Consider treating bulls prior to joining with an additional treatment if necessary. Don’t mix treated animals with untreated (clean) animals for at least 6-8 weeks after treatment to avoid reinfestation.
INDICATIONS: Treatment of diflubenzuron susceptible biting lice (Bovicola bovis) and sucking lice (Linognathus vituli, Haematopinus eurysternus and Solenopotes capillatus) in cattle. Treat all animals in the mob and check the accuracy of the applicator before and during treatment.
Coopers recommends a single treatment in April/May to provide season long protection through winter. Additional treatment may be required if re-infestation occurs.
The withholding period for cattle meat is 10 days. Efficacy is not affected by moderate rainfall after application.
Now it’s starting to dry out again and the warmish conditions, with some residual moisture, are creating an environment for round worms to persist. Cattle grazing pasture are usually infected with a wide range of round worms, one in particular is Ostertagia ostertagi, also known as the small brown stomach worm.
The brown slender adult worms about 10mm long are found on the surface of the abomasum. There are three different types of infection found.
Type 1 infection is when ostertagia develop through the life cycle normally and the number of adult worms depends on the number of eggs ingested, common in weaned beef calves in late winter early spring.
Type 2 infection is when the larvae are inhibited in the mucosa of the abomasums and accumulate in large numbers. Cattle show no symptoms except decreased weight gain. The larvae can remain inhibited for 4-6 months.
Type 3 infections are when huge numbers of the larvae develop in the mucosa developing at once destroying the structure of the stomach surface. This is frequently seen in the autumn in yearling and 18 month old cattle, or cows after their first calf. Cattle develop scours, lack of appetite, weight loss and are susceptible to other diseases.
Ostertagia eggs are resistant to cold and survive well in cool conditions. The larvae develop well at temperatures as low as 10 degrees. Depending on the age of the calf, larvae picked up in the spring and early summer tend to become inhibited and large numbers accumulate. Then in late summer to autumn the larvae develop through to adults and type 2 infections are found.
Treatment is as easy as good autumn drenching program. The ostertagia are usually present in high numbers as inhibited larvae in the mucosa and then as adults in the lumen anthelmintics that can penetrate into the tissue and kill the larvae are needed.
Levamisole works reasonably well against adult worms, but will only kill about 30% of larvae. Benzimidazoles (white drenches) vary in their ability to kill. Oxfendazole and Fenbendazole are estimated to kill 85%, while albendazole is reported to kill 50-60%. The mectins generally have good efficiency against inhibited larvae with trials showing about 99% kill rate.
If you have any questions about an autumn winter drenching program for your cattle then drop in and see the Landmark Daniel Walker team.
BOVINE RESPIRATORY DISEASE (BRD)
Pre-Feedlot BRD vaccination with Bovilis MH+IBR is now more flexible
Bovine Respiratory Disease causes between 50% and 90%1 of sickness and death in Australian feedlots, and it’s estimated to cost the Beef Industry $60 million annually.
BRD is a complex disease involving many contributing factors that, if combined, compromise the respiratory defences of affected cattle, allowing infection to establish in the lungs and produce severe, often fatal, pneumonia. Contributing factors include stressors such as transport, dietary changes, feedlot induction, pen competition and mixing of cattle from different sources.
Over the last two years major Australian feedlots have started paying a premium for cattle pre-vaccinated with Bovilis MH + IBR from Coopers Animal Health.
Bovilis MH + IBR is a combination vaccine given subcutaneously that helps to control bacterial and viral causes of BRD. Controlling BRD has been proven to help cattle perform better in the feedlot.
Bovilis MH + IBR now has a flexible inter-vaccination interval (the time between the first and the second dose) of 14 to 180 days.
This recently achieved new label claim has been possible due to scientific data generated in Australian cattle and is great news for the Australian Beef Industry.
Cattle producers supplying cattle to feedlots can now pre-vaccinate at the same time as other normal management practices at weaning and reap the rewards at sale time. Feedlots can now feel safe in the knowledge that their traditional suppliers will have plenty of time to vaccinate pre-sale.
Resellers can confidently stock Bovilis MH+IBR as it becomes part of standard cattle management rather than a last-minute rush order.
Paul Speers, Marketing Manager for Coopers Animal Health says, “sales of Bovilis MH+IBR have increased by over 50% as feedlots and backgrounders recognised the benefits the vaccine provides in helping to control BRD.
The main barrier to use has been the short window available to apply the vaccine prior to sale. By providing flexibility in the interval between doses we’ve made it possible for cattle producers to pre-vaccinate their cattle at a time that fits with other farm activities. While we have been working hard with our pre-vaccination partners to ensure the vaccine is available to producers.”
MULTIMIN INJECTION FOR CATTLE
Weaning is a stressful time for calves. This stress can put increased demands on the immune system and in turn, the trace minerals essential for normal immune function. Providing a boost of trace element at weaning can help promote strong healthy weaners with greater potential to gain weight. Trace minerals are also important for bone development, muscle function and general growth.
Multimin quickly increases the trace mineral status of cattle before critical events when the animal’s trace mineral demand is greater. By using Multimin before a critical event, trace mineral levels will potentially remain higher and return to optimal levels sooner, assisting in animal recovery.
Multimin is an injectable source of zinc, manganese, copper and selenium, ideal for topping up trace minerals prior to critical events such as joining, calving, marking, weaning) when demand may increase.
WORM EGG COUNT TESTS
Which WEC test should I choose? – Cattle Testing Dawbuts has recently begun offering a new Cattle Sensitive test which offers increased sensitivity in WECs for cattle farmers. The new technology, known as Mini-FLOTAC, offers a WEC with a sensitivity of 5 EPG allowing meaningful results to be returned to cattle farmers.
Mini-FLOTAC is recommended to all cattle farmers wishing to complete WECs, particularly for ‘before and after’ testing of mobs to check drench resistance.
All species testing (sheep, cattle, goats, alpaca, horses) Individual Worm Egg Counts An individual worm egg count will provide you with a very valuable range of figures. It will provide 15 WEC results plus an overall average. Complete this test if you wish to identify the worm burden and gain insight into the variability of the worm burden across your flock or mob.
Pooled Worm Egg Counts: Pooled counts are helpful for detecting a worm burden and are a cost effective way to monitor the worm situation. It will provide 3 pooled WEC results plus an overall average.
Larval Differentiation: After a worm egg test is conducted, the eggs are cultured for 7 days and hatch into larvae. These larvae can then be identified to diagnose what type of worm is present. This is valuable information when selecting an appropriate drench to target particular worm species or prevent further drench resistance.
Drench Resistance: Testing Is the ultimate of worm testing! This test helps identify which drenches are working against particular worms on your property. Drenches that don’t remove more than 95% of the worm burden after treatment are no longer effective and without this knowledge it is costing you money and time and only adding to your drench resistance issue. Every property is different when it comes to drench resistance. A Drench Resistance Test should be conducted every 2 years.
4-6 groups of 15 animals are drenched with different drenches and one group is left untreated. 10-14 days later a rectal sample is collected and worm egg count is conducted to see how well the drench worked.
Individual WEC Testing for ASBVs This is ideal for stud producers using Australian Sheep Breeding Values and want to include WEC values into their selling data or improve worm resistance through breeding. An individual WEC is carried out for each identified sample.
For more information visit www.dawbuts.com
A new Cattle Sensitive test which offers increased sensitivity in WECs for cattle farmers.
VACCINATION AGAINST PULPY KIDNEY IN CATTLE
Pulpy Kidney (enterotoxaemia) is a disease that can cause sudden death in cattle. It often affects animals in good body condition and can be difficult to diagnose. Vaccination is an important tool in the prevention of deaths due to Pulpy Kidney disease.
WHAT IS PULPY KIDNEY DISEASE?
Pulpy Kidney disease generally presents as sudden death. Occasionally in-coordination and convulsions may be observed prior to death. Multiple animals may be affected, often the heaviest animals in a mob.
WHAT CAUSES THE DISEASE?
The disease is caused by the bacteria Clostridium perfringens Type D and the toxin it produces. The bacteria and toxin can exist in small amounts in the gut of healthy animals. Normal movement of material through the intestine keeps the levels of bacteria and toxin very low so that no disease occurs.
Factors that alter the environment in the gut may allow these bacterial spores to germinate (or activate), multiply rapidly and produce high levels of toxin, resulting in disease and death.
WHAT ARE THE RISK FACTORS?
Sudden changes in the amount or quality of feed, such as introduction to lush pasture or grain-based diets, can alter the gut environment and allow the bacterial spores to germinate, multiply and release toxin. Pulpy Kidney is therefore most likely to occur during periods of rapid pasture growth and high feed availability, especially when animals are moved from a
low-quality feed onto these pastures.
MANAGING THE RISK
There is no treatment for Pulpy Kidney disease so prevention is critical.
The first defence against Pulpy Kidney is to avoid those situations that can contribute to bacterial growth and toxin production within the animal, such as a sudden change in diet. In practice these situations may be difficult to avoid during normal farm management practices. Thus vaccination against Pulpy Kidney is an important, and practical, tool in the management of this disease.
Zoetis offers a range of vaccines for the prevention of pulpy kidney disease in cattle. In previously unvaccinated animals, a primary course of two vaccinations, 4-6 weeks apart, is required. These two basic doses of Ultravac 5in1 or Ultravac 7in1 should provide effective immunity against pulpy kidney disease for three months. Booster doses, using Ultravac 5in1, are therefore necessary to maintain immunity against pulpy kidney disease in cattle and should be given at appropriate intervals according to local and seasonal conditions.
At a minimum, annual booster doses of Ultravac 5in1 or 7in1 should be administered.
The risk of Pulpy Kidney disease will vary depending on farm management practices. Contact your local Zoetis Representative, Zoetis Technical Services or your local veterinarian for specific advice to suit your situation and level of risk.
Both Ultravac 5in1 and Ultravac 7in1 can be used for up to 30 days after opening (see label for storage instructions).
CONTROLLING LIVER FLUKE IN CATTLE
Liver fluke is a serious parasite of cattle that can cause significant economic losses through reduced production, ill health and sometimes death. Adult fluke damage the bile duct and feed on blood, leading to loss of condition, anaemia and ‘bottle jaw’. Cattle mainly ingest the infective fluke cyst (metacercariae) on vegetation over late summer and autumn as they graze near wet areas, such as dams and slow-moving streams. Strategic anthelmintic treatment aims to reduce the number of fluke in the host and the number of fluke eggs on pasture. For beef cattle, this usually requires two treatments annually administered in autumn and in late winter/early spring. When choosing an anthelmintic to treat liver fluke in autumn, it is important to select a product that provides effective control of all three stages of this parasite (e.g. contains triclabendazole).
Elanco control options include Fasinex™ 240 Oral, Fasimec™ Cattle Oral and Fasimec Cattle Pour-On all contain triclabendazole, the only active ingredient that kills all three stages of liver fluke: early immature (up to 6 weeks), immature (6–9 weeks) and adult fluke (10 weeks and older). Fasimec Cattle Oral and Pour-On also contain ivermectin or abamectin respectively.
Is it an issue? Have you had problems before?
Grass tetany is the result of magnesium deficiency in sheep and cattle. The signs of grass tetany in sheep and cattle are muscle twitching around the face and ears, excitability, convulsions and death in extreme cases.
The accepted rule of thumb is for every 1 animal which has signs of grass tetany 20 others are affected.
Grass tetany is more likely to occur in fast growing lush pastures that are high in potassium. The grass is not necessarily low in magnesium but the high potassium levels reduce the absorption of the magnesium leading to a deficiency in the animal. High nitrogen levels in the grass also reduce magnesium absorption and induce grass tetany.
‘Provimins Midmag’ for Sheep and Cattle and ‘HiMag’ for Cattle Only are a palatable source of magnesium that provides the animal with the required level of magnesium to help with the control of grass tetany. It’s a weatherproof loose lick, fed ad-lib for easy application.
They contain 12 vitamins and minerals for added livestock growth performance on fast growing high moisture grass.
For Beef Cattle 50 – 100g per day is required, Beef Cows 100 – 125g per day, Weaners 40 – 80g per day, Sheep 15 – 100g per day, and Lambs 8 – 45 g per day.
MidMag contains 15% Magnesium and HiMag 20% Magnesium.
Talk to Landmark if you stock have been showing signs of grass tetany.
Nitrate Poisoning can cause large losses of sheep and cattle especially in extensive situations. Knowing the main triggers and situations where nitrate poisoning is possible and put in appropriate precautions is recommended as nitrate poisoning can hit quickly and cause large losses.
When the ruminant animal eats a plant the following process occurs; Nitrate (NO3) > Nitrite (NO2) > Ammonia (NH3) > Microbial Protein > Amino Acids.
When higher than normal amounts of nitrates are consumed, the nitrates are converted to nitrites quicker than nitrites can be converted to ammonia, leading to a build up of nitrites in the rumen. The nitrites are then absorbed from the rumen and nitrate/nitrite poisoning occurs. High levels of nitrite in the bloodstream can cause changes to haemoglobin which carries oxygen around the body.
The result of nitrate poisoning is the animal essentially starves of oxygen. Lack of moisture, soil temperature and sunlight can all affect this process and cause nitrate/nitrite poisoning. Nitrate poisoning is more common in stunted plants that have a purple discolouration and on soils that are high in nitrogen. Cloudy, rainy and frosts can also increase the incidence. Nitrate poisoning is possible on stressed cereal crops, canola crops, brassica crops, pastures, weeds such as capeweed, variegated thistle, etc and also millets and some forage sorghums . Some herbicides can also increase the accumulation of nitrates in the plant. Plants that have had high levels of potash and nitrogen fertiliser can be more prone to nitrate poisoning.
Plants that have been moisture/cold or sunlight stressed may not be able to convert the nitrates absorbed by the roots into plant protein resulting in a build-up of nitrates in the plant. If hay is to be made out of suspect plants it is important to make sure the hay is properly dried. If large levels of nitrates are present and the hay is damp the nitrates convert to nitrite in the stack and when the hay is fed out nitrite poisoning occurs. Making silage out of suspect plants are often a better option than hay as the fermentation process can reduce the nitrate levels. If high nitrate levels are suspected it is advisable to get a nitrate/nitrite level performed via a feed test. U
Signs include diarrhoea & abdominal discomfort, rapid respiration, difficulty in breathing, trembling & staggering, convulsions, eventual death, and blood on post mortem (soon after death) appears to be a dark brown, chocolate colour and thick in appearance.
Get a nitrate/nitrite level done on suspect paddock to see if levels are safe to feed. Don’t put hungry stock onto suspect pasture/crops. Give them a feed of hay before putting them onto the paddock. Introduce the animals slowly onto the risky crop/pasture as the rumen bugs can handle small amounts of nitrates and you can slowly increase the amount given over time.
Supply a carbohydrate source as the energy source helps the bugs better utilise the nitrates. You can introduce a small number of stock and closely monitor to see if you see any signs and remove immediately if any unusual signs are seen. Monitor stock regularly when grazing suspect crops.?Try not to graze pregnant animals on the suspect crops as nitrate poisoning can cause abortions. Animals should receive a 5 in 1 vaccination before going onto crop as the change in diet can induce pulpy kidney.
Treatment: Urgent veterinary treatment should be sought if nitrate poisoning is suspected. For more information contact Landmark.
Red legged earth mite & blue oat mites.
Earth mites are a pasture pest that can be our worst night mare as we approach colder winter months. There are two types of earth mites to be conscious of, one being the Red legged earth mite (RLEM) and the other being the Blue oat mite (BOM). Both look very similar and cause the same damage. It is very hard to identify the difference between the two without close examination. The BOM will be seen to have a small white spot on its back.
The mites are native to South Africa however have called Australia home for the past 83 years. They have thrived during these years spreading right across the country where climatic conditions favor them. Unfortunately there are no predators for the mites which have allowed them to achieve this feat.
The eggs hatch in the autumn, approximately 20 days following either, a) 10-15mm of rainfall or b) Daytime temperatures are below 15 to 19 degree C for several days. It will be seen that the mites will be very active during the autumn months and slowly decrease from July to early September when they will rapidly increase during the spring before tapering off over the summer.
The RLEM and BOM cause majority of damage to newly sown crops and pastures. Typical damage is identified by silvering and whitening of attacked foliage, which is caused by air replacing sap at the feeding sites. If your crop is looking off colour (dull and silver looking) then it may be necessary to get on hands and knees and inspect closely. Mite numbers in affected paddocks are regularly reported as more than 120,000 per square metre – the equivalent to running one extra sheep per hectare. On a 2000 hectare property that can mean a mite infestation eats the same as 2000 sheep.
There are a number of different methods to control RLEM and BOM. If you have had problems in the past and not known what to do, then don’t hesitate to drop in to Landmark to discuss control options.
TRACE ELEMENTS FOR CATTLE
For a long time now trace elements have been recommended by many people in the cattle industry. Farmers have questioned their results, as it is very difficult to see a measured result.
One reason why, is that trace element requirements are not constant.
The needs of the animal will vary depending on its productive status. For example, when a cow is in late pregnancy, the gross copper requirement is greater, so as to build large reserves of copper in the foetus. Additionally, at time of high productive demand, mineral utilisation may be increased.
A way to overcome this problem is to strategically supplement trace minerals prior to critical events. The concept is to top up the animal with essential trace element that are needed for physiological function of the animal at critical events. The key critical events for beef productions are calving and lactation, joining and young growing cattle. Next week we will look at the above periods.
If you have any questions on trace elements call Richard at Landmark.