Dairy & Cattle
Calf diarrhoea (scours) is normal often a normal part of the calf’s gut developing and getting used to milk and feeding outside the womb. The best assessment of whether or not scours is a problem is to look at the mob or pens of calves; not just considering the consistency of individual faeces, but assessing the whole group and the whole calf (not just the faeces).
Causes of Scours
The predisposing factors for scours are similar almost regardless of the cause. Some of the more common factors in outbreaks are inadequate colostrum intake, poor feeding hygiene, poor feeding routines with poor quality CMRs (calf milk replacers), inadequate housing and overcrowding.
The pathogens involved in calf scours vary from
- None (as with simple nutritional scours)
- Viruses (Rotavirus and Coronavirus)
- Protozoa (Cryptosporidium and Coccidia)
- Bacteria (Salmonella and E.coli)
Management of Scours
Diagnosis of the infectious agent is very useful, as it can influence both prevention and treatment. This may be achieved by stool samples but post-mortem tissues might be necessary as well. Post mortem exams and examination of the scene by an experienced vet can be very insightful.
Treatment of scours is based on the following:
- Good fluid therapy
- This is the cornerstone to treatment of calf scours. Severe dehydration caused by diarrhoea can lead to organ failure and death. Balanced fluid therapy not only corrects water deficits, but also corrects electrolytes, acidosis and energy deficits as well.
- Antimicrobial therapy
- These are useful when bacterial causes of diarrhoea are involved.
- Pain relief
- This can be a dramatic help, as pain free calves will suckle better and rehydrate themselves.
Prevention and control
This is best achieved in shed by patience, cleanliness and attention to detail. Provision of good quality feeds, good hygiene, careful observation and prompt/vigorous treatment of calves is recommended.
Setting up the calf shed with batch management (all in, all out) and vaccination of dams against E.coli, Salmonella and rota/corona viruses can be very helpful, provided the calves are fed adequate colostrum!
Give us a call if you have any questions about setting up calf sheds, establishing treatment protocols or training staff.
At the time of writing Mycoplasma has been confirmed on 39 farms, the most recent being a farm near Cambridge in the Waikato. It seems it will only be a matter of time before it is found in the BOP.
Mycoplasma bovis is a bacterium that causes a range of diseases in cattle that don’t respond to treatment. It is highly undesirable to have it in NZ or on your farm because of its cost in terms of productivity and culling. However to be kept in perspective it is not the end of the world and is not a reason to give up on farming. Most countries including Australia have Mycoplasma and farmers in those countries have learnt to live with it. On the plus side is that it is a relatively slow moving disease and there is no danger to humans and no risk to humans from consuming meat or milk products from infected animals.
In adult cattle it causes:
· Non responsive mastitis usually involving multiple quarters. The affected quarters are swollen (rubbery) but not hot or painful and will rapidly dry off. The cow does not get sick.
· Abortions or early small calves.
· Swollen joints that are painful and hot and cause marked lameness.
· Severe pneumonia starting with a hacking cough
· Ear infections starting with a droopy ear & sometimes head tilt
· Conjunctivitis leading to sticky white eyes
· Swollen legs/joints that are painful & hot
All these can be symptoms of other common diseases but the key is that response to treatment is poor or several animals are affected or individual animals have more than one sign. If suspicious ring us as soon as possible.
A big part of the problem with Mycoplasma is that it is a wretched disease to diagnose. The immune response is variable, and the shedding of the organism is affected by stress factors such as pregnancy, lactation, transport etc. This means that even a perfect test will miss some carrier animals because they are simply not shedding at the time of testing. To be reasonably sure a herd is negative requires several tests at intervals. Added to this is that some tests also have high false positives.
· For animals showing symptoms then a sample of the relative exudate i.e. Milk, joint fluid etc will be diagnostic.
· For milking herds several bulk samples over time will determine herd status.
· For dry stock there is no easy answer. Nasopharyngeal swabs are the best bet but are difficult to do and probably have to be repeated to give a true indication of herd status.
Mycoplasma is mainly spread by direct contact between infected animals. It potentially can also be spread on equipment that has been used on infected animals eg milking machines, AI and veterinary procedures. It is spread through bodily fluids but not as far as it is known through urine or faeces. It is not windborne or spread through rivers and streams.
Prevention is focused on farm biosecurity and cleaning & disinfection. For detailed notes visit the MPI and DairyNZ websites.
· Where practical limit cattle movements onto your farm. Mycoplasma can be present in apparently healthy animals and there is currently no commercially available pre-movement test that can be applied to detect infection.
· Create boundary buffer zones to prevent contact with neighbours stock. Do not graze paddocks at the same time as neighbours stock is next door.
· Do not buy in or lease stock. If you do ask questions about the farms stock health and history. A supplier farm that breeds its own stock will be safer than someone who buys stock from elsewhere and grows it.
· If you have to graze out stock check on the biosecurity of the grazier and who else grazes there and what their history is. Talk to your grazier about not mixing mobs and avoiding nose-to-nose contact with other stock. Insist your carrier transfers your stock in a clean truck by themselves.
· Keep all newly arrived stock on farm separate for at least 7 days. Monitor them for signs of disease and if in doubt call a vet.
· Make sure animals have NAIT tags and all sending and receiving movements are sent to the NAIT sysyem
· Manage access on farm. This includes limiting people who come on to farm and to where. It also includes equipment and stock trucks.
· Have a suitable cleaning and disinfectant protocol for boots, equipment and visitors. Equipment, boots etc have to be clean before they can be disinfected. Suitable disinfectants include 1% Virkon, 0.2% citric acid and Trigene.
Managing the disease:
There has not been a lot come out about managing Mycoplasma because the hope is we will eradicate it. However overseas experience suggests that stress plays a huge part in managing the disease. Key points are:
· Ensure all animals are kept healthy and in good condition.
· Be proactive with diseases that can be prevented e.g. BVD, worms, facial eczema, trace elements, mastitis etc etc
· Minimise stress e.g. Feed, transport, housing, time walking, overcrowding, yarding time etc.
· Identify and cull clinicals ASAP to minimise spread
Herd Fertility and InCalf Programme
Herd fertility is a fundamental driver of farm productivity and profitability. If your cows are failing to get in calf, or not getting in calf in a timely manner, this will be affecting your bottom line through increased culling and less days in milk.
Improving herd fertility isn’t easy. It takes time to implement changes and for
these improvements to flow through as results in the herd. Also, there is very
rarely a silver bullet. Herd reproduction is complex and there are multiple
areas that impact on the overall performance.
The InCalf program was introduced to New Zealand as a result of the declining
fertility of the national herd. It is a herd fertility advisory program that aims to:
- Assess herd fertility and potential economic gains
- Identify key areas for improvement
- Implement changes that fit with your system
- Review those changes to ensure they were successful
We know the importance of good herd fertility on farm, and are committed to improving reproductive performance across the district. At Te Puke Vets, we have four InCalf advisors at the clinic who are happy to talk to with you. If you would like to find out more about the InCalf programme, click the photo on the right.
Having non-cycling cows at mating is a common problem faced on farm. Non cyclers reduce herd reproductive performance as they don’t get mated early, their first heat is sub-fertile and some don’t have regular returns for subsequent mating’s. Having a proportion of cows not cycling at the start of mating is entirely normal, but not ideal.
There are many risk factors that will contribute to a cow becoming a non-cycler including:
- Calving date (late calvers),
- Age (young),
- Breed (Friesian, Holstein),
- Undergrown young stock,
- Body condition score (especially if light at previous calving)
- Reproductive health issues
Assuming heat detection is OK, in the ideal situation 85% of the herd should be seen cycling by the planned start of mating. It is important to ensure pre-mating heat detection starts 5 week prior to the planned start of mating so you have the information available to know if you have a non-cycler problem.
Reducing the number of non-cyclers can be highly profitable; however there will always still be a small proportion of anoestrus cows every mating, regardless of prevention strategies. Intervention with non-cycling cows with hormonal treatment can be successful and is most profitable if carried out early.
Our clinic is very familiar with all the latest programs – there are a number to choose from. The biggest trap in anoestrus cow programs is not getting organised early enough. Please don’t hesitate to contact us if you are concerned about the level of non-cyclers in your herd this year.
Endometritis is a common condition following calving. Much attention has been drawn to it in recent years as researchers have fully measured impact on subsequent fertility. Endometritis is the inflammation of the inner lining of the uterus.
During calving bacteria enter the reproductive tract, and in a proportion of cows an infection persists. The infection involves production of a white-yellow pus and occasionally smell. Some, but not all cows show an external discharge of pus and mucous.
This will disturb the normal hormonal function of the uterus, delaying cycling and making the uterus less likely to support an embryo. Reductions in submission rate and conception rate can result in reductions in pregnancy rate (approximately 25% reduction at day 21 post service). Reductions in final not in calf (empty) rates have also been reported.
What should I do?
Cows affected by endometritis don’t always have a discharge making it difficult to determine the level of infection in the herd. Metrichecking can assist with a more accurate diagnosis of infected cows and allow them to be treated in the timely manner.
The most common treatment is infusion of an antibiotic into the uterus. Broad spectrum injectable treatments may also work. These treatments improve the fertility outcomes of affected animals.
Retained membranes, assisted calvings, twins, abortion, downer cows and concurrent disease (eg. Ketosis) are all associated with increased rates of endometritis. If you have had problems with any of these conditions this spring, or notice vaginal discharge contact the clinic as endometritis may be impacting on your reproduction.
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Local farmers, associated rural communities and Te Puke town people have supported Te Puke Vet Centre for over 50 years. During those years scores of receptionists, nurses and vets have lived and enjoyed the benefits of this great town and area. It is very important for Te Puke Vets that we are strongly integrated with the local community and as part of that we are proud to support many local schools, sports clubs, service organisations and community events.