Category Archives: Animal Health

SHUTTING THE DOOR ON PATHOGENS CAUSING BOVINE MASTITIS: THE ‘TEAT END’ STATUS

Would you leave the main door of your house unlocked? No, of course not, as it works as a barrier to stop intruders from getting in. When it comes to preventing mastitis in dairy cows, the teat end also acts as a barrier that protects from pathogens causing bovine mastitis. In this post, we will help you evaluate the state of the primary protection against teat

PRPREVENTING BOVINE MASTITIS: WHY CHECKING TEAT STATUS IS SO IMPORTANT?

The teat sphincter and teat canal are important primary barriers against pathogen invasion into the udder and prevent bovine mastitis.

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Lesion scoring technique for Eimeria in chickens

When talking about the diagnosis of Eimeria in chickens, most people think of the oocyst count (OPG) and now PCR as the gold standard methods for obtaining the most accurate diagnosis. This is partly true, however it is very important to remember that the earliest diagnosis is still only possible with the classical lesion scoring technique implemented in 1970 by Johnson & Reid. Some factors can affect the lesion scoring method and should therefore be taken into consideration: proper selection of birds, careful necropsy procedure and accurate training for identification. (Read more)

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The oocyst count, commonly referred to as OPG (oocysts per gram of faeces), has been used for decades as the most common way to detect Eimeria oocysts on farms and it is still widely performed with the same purpose. However, we should point out its limitations:

• The presence of oocysts does not necessarily mean that a coccidiosis outbreak will soon occur on that farm;

• Affected birds with macroscopic lesions in the gut do not yet produce and shed oocysts.

In spite of this, the oocyst count has been shown to be very useful when monitoring the farm with weekly sampling, as the results can give us an indication of either the development of anticoccidial resistance or of the vaccine intake and onset of immunity after coccidiosis vaccination.

The PCR technique for Eimeria – recently introduced as a routine test in more and more diagnostic labs – also has advantages and limitations. The main advantage is the possibility of an accurate species identification of the Eimeria spp. contained in the sample.

In fact, field samples may contain debris and impurities and even if they are well preserved (refrigeration at 4-8ºC) and the typical morphology of each Eimeria species is easily recognizable, Eimeria spp. identification may be difficult.

Moreover, shape can be altered if the oocyst sporulates, thus an error range always has to be taken into account when species identification is done through microscopic appearance.

Whereas the main disadvantage of this technique lies in the fact that we do not know whether the Eimeria DNA that has been amplified comes from a live and infective parasite or from DNA debris contained in the sample.

This is why, the above having been said, lesion scoring for Eimeria in chickens today still remains the earliest method of diagnosis for coccidiosis outbreaks together with clinical signs. As there are some variables that can also influence this technique, in order to achieve the most reliable results, we should briefly analyse them:

1. Selection of the birds

Before necropsy, it is essential to know the Eimeria prevention strategy used on the farm:  vaccinations or anticoccidials.

It has been shown that the existence of gut lesions is not necessarily accompanied by clinical signs of coccidiosis in poultry (Williams et al., 2000). It has also been shown that immunized birds may display lesions and high oocyst counts, with no growth retardation or clinically overt disease.

As for the number of birds to be examined, generally, a total of 5 to10 birds from each house would be reasonable. Regarding the age, unless in the presence of a coccidiosis outbreak, in the case of vaccinated birds, the best age to check the safety of the vaccine is between 18 and 24 days of age. On the other hand, efficacy of the vaccine is better checked by performing necropsy between 28 and 35 days of age.

If anticoccidials are used, the best age to check the efficacy of the compound used in the feed is between 25 and 35 days of age. These birds should be of the average weight of the batch, and be alive at the time of sampling, not debilitated or fasted.

2. Necropsy procedure for Eimeria lesions detection

As previously mentioned, it is crucial that birds examined for gross lesions (at least 5 per batch), are alive and within the appropriate age range. If multiple groups are inspected, it is better to sacrifice one group and then another to reduce post-mortem artifacts.

The intestine is the first organ to decompose after death. Postmortem changes negatively influence the assessment of pathological changes due to Eimeria infestations in the gut. Make the sacrifice humanely with the least possible stress.

3. Training for Eimeria lesion identification

To complete the inspection looking for Eimeria lesions in a systematic way, consider the segments of the intestine that are shown in the slide share below: duodenum, upper and lower mid-intestine, rectum and caecum.

Do not expose the inner surface of the intestine until you have inspected the outer wall. It is important to record any change in thickness, colour or presence of spots, either petechiae or white spots.

Expose the inside of the digestive system. Observe and describe the content found:  amount and appearance. Inflammation of the intestine can sometimes be identified immediately after cutting the wall longitudinally, as it tends to fall back on itself.

This only happens when it belongs to a bird that has been recently sacrificed. List all the lesions observed, their location, colour, appearance, distribution, shape, etc. Whenever possible, take photos of the lesions.

Find some pictures and description of the typical lesions of the seven Eimeria spp. in the video above.

To sum up, in order to perform a careful coccidiosis diagnosis, we need to work with all three above-mentioned methods together and be well aware of the advantages and limitations of each.

References

Williams R.B., Catchpole J., 2000. A new protocol for a challenge test to assess the efficacy of live anticoccidial vaccines for chickens. Vaccine 18(13): 1178-85.

Johnson J., Reid W.M., 1970. Anticoccidial drugs: lesion scoring techniques in battery and floor-pen experiments with chickens. Exp. Parasitology 28(1): 30-6.

Coccidiosis in poultry does not only come from Eimeria tenella

Eimeria tenella is by far the most widely detected species on farms when routine lesion scoring is performed. However, it is well known that most of the time Eimeria infections are multiple. On the other hand, during last decade the egg sector has probably undergone the biggest changes, with an ever-increasing percentage of cage-free laying hens, especially in Europe.

Generally in layers and breeders we distinguish between caecal and intestinal coccidiosis. Caecal coccidiosis is due to Eimeria tenella  that is confined to the caecum and consists of the presence of hemorrhages on the outside or inside of the wall of the caecum.

This acute infection occurs most commonly in young chicks and is by far the most widely diagnosed in the field due to its typical lesions and location. For this reason, a common belief is that Eimeria tenella is the most prevalent all over the globe. In fact, macroscopic lesions are amongst the most pathognomonic with blood or typical molds in the caecum and common findings of bloody droppings in the litter.

https://eimeriaprevention.com/news/coccidiosis-in-poultry-eimeria-tenella-in-laying-hens/

A common belief is that Eimeria tenella is the most prevalent all over the globe.

However, most serious cases of intestinal coccidiosis are caused by Eimeria necatrix (and fewer, but still serious, by Eimeria brunetti). Both develop within deeper tissues of the small intestine and besides Eimeria tenella are major pathogens of poultry. Eimeria necatrix and Eimeria brunetti mainly affect birds of more than 8-9 weeks of age.

Recently, the evolution of the production systems with an ever-increasing percentage of laying hens that are floor-reared or reared in systems such as aviaries has shown a clear influence on the incidence of coccidiosis outbreaks, caused not only by Eimeria tenella, but also quite frequently by Eimeria necatrix.

Production systems with laying hens that are floor-reared has shown a clear influence on the incidence of coccidiosis outbreaks, caused by Eimeria necatrix.

The greatest evidence of this new situation is that coccidiosis vaccination in laying hens has increased considerably within the EU but also outside it.

Many egg producers have taken the decision to vaccinate all their flocks against coccidiosis, as the disease has started to appear more frequently in these semi-floor type rearing systems.

Many egg producers vaccinate against coccidiosis, as the disease has started to appear more frequently in semi-floor type rearing systems.

But why is that? Eimeria infections appear everywhere that birds have the opportunity of coming into contact with their faeces and pecking them. When most of the laying hens were reared in conventional cages, coccidiosis hardly occurred at all and a few cases appeared on those occasions when hens could peck the manure belt of the floor above.

So what happens nowadays? Hens reared on the floor or in aviary systems – where hens are reared totally or partially on the floor- clearly come into contact with their faeces.

However, it could also be the case with hens reared in furnished (enriched) cages as faeces can accumulate in some areas of the cage, such as the nests, and don’t fall on the manure belt below the cage. Every contact with faeces exposes the hen to a possible coccidiosis challenge as Eimeria oocysts are ubiquitous.

This is why nowadays we need to work on Eimeria prevention in all the three above- mentioned production systems: floor-reared, aviary systems and sometimes also with enriched cages.

Vaccination is well recognised as the most convenient Eimeria prevention strategy in laying hens, as one vaccination can protect birds for their entire lives, as long as certain conditions are met. And this is where the challenges lie:

• Choice of vaccine

• Day of vaccination & route of administration

• Management after Vaccination

In order to find out more about the challenges egg producers have to face when vaccinating for coccidiosis, have a look at the following article: Coccidiosis and welfare-friendly production systems for laying hens. A new connection.

NMC, THE LARGEST EVENT ON MASTITIS IN CATTLE

As the date for the international conference of the National Mastitis Council (NMC) is approaching (June 2018), we’d like to give you an insight into what to expect at this year’s congress. As you may know, the hot topics of the congress will be antibiotic resistance, bedding management and mastitis and immunity, among others. We asked the NMC 2nd Vice President to answer some questions about what will be happening at the most important event on mastitis in cattle and review with him how the Congress has evolved over the last few years.

INTERVIEW WITH MR. SARNE DE VLIEGHER (NMC 2ND VICE PRESIDENT)

TIPS TO PREVENT CONTAGIOUS MASTITIS IN CATTLE

After talking to several vets, we realized that they don’t check the milking machine as often as they should. We will not get tired of repeating this message: the role of the milking machine is crucial to the prevention of mastitis in cattle!

Have you ever checked the milking machine vacuum?”…

When talking to vets and asking them this question, usually we hear the answer “not as often as I would like” or “I only go to the milking parlour to clean my boots after working…”

We have created this series of posts in order to facilitate your approach to the milking machine and avoid the risk of having contagious mastitis in cattle.

In previous entries, we described the milking machine to you, and then we also gave you some tips to check the milking machine visually.

In this  third post we will provide you with a list of easy parameters to check during your visit to the “boot cleaning” place so you can prevent contagious mastitis in cattle.

THE “STATIC TEST” AND ITS MAIN ADVANTAGES

The term “static testing” has traditionally been used to describe tests that are performed with the machine running but with only air flowing through the system (Reinemann, 1996).

The static test includes the following:

Vacuum levels in the plant: Vacuum levels are checked at various locations throughout the plant to ensure that there is no significant loss of vacuum between the pump and the teat end, and that the plant is set at the correct level. A drop in vacuum level would indicate that air is leaking into the system. The accuracy of the vacuum gauge is also checked. We have talked before about the role that incorrect vacuum can play in causing mastitis in cattle.

Vacuum reserve: Adequate vacuum reserve is needed to ensure that stability of pressure is maintained in the plant throughout milking. The ISO has made several recommendations for vacuum reserve. It must be remembered that these are minimum recommendations, and ideally, new plants should exceed these levels significantly.

Systems with a low vacuum reserve will have difficulty in maintaining stable vacuum levels during milking.This may result in an increased number of liner slips and irregular vacuum fluctuations, which may affect the incidence of mastitis in cattle and poor milkout. The vacuum pump should have sufficient reserve capacity (known as the Effective Reserve or the Manual Reserve) to cope with accidental air admission through the teatcups during milking. The adequacy of reserve pump capacity can be estimated in the following way:

Note the vacuum level (preferably, in or near the receiver) with all units shut off.

Then, open the vacuum shut-off valves to one unit (or two units in systems with more than 32 units).

If the vacuum level does not fall more than 2 kPa, then the Effective Reserve is likely to be adequate.

If this test is carried out under the same conditions each month, and the vacuum level recorded for 1 or 2 clusters when fully open, then gradual changes in reserve pump capacity due to air leaks, pump wear or regulator malfunction can be monitored systematically (NMC, 1998).

Regulator function: It is important that the regulator functions correctly so that a stable vacuum level can be maintained throughout milking. Regulators commonly become blocked with dirt, thereby reducing the amount of air leaking into the system, but occasionally the mechanism becomes defective.

Pulsation: The most common pulsation faults include cracks or splits in the pulse tubes, foreign material (dirt, grit, straw, feed particles or insects) under the pulsator valve seats or lodged in the air inlet ports (NMC, 2006).

The role of the milking machine is crucial to the prevention of mastitis in cattle.

General condition of the plant, rubberware, etc.: The plant should be examined for any perished rubberware, leaky valves, etc., and its overall condition noted. Liner condition should be assessed and the frequency of change checked to ensure that the liners are replaced at the correct intervals.

All these points can fail due to the use and non-optimal maintenance of the milking machine, and every point that fails is another factor that can have a huge impact on mastitis in cattle.

We hope you find this information useful, and now is the time to apply these tips. Remember to subscribe to our Uddernews if you want to receive updates!

Content originally created for “the Mastipedia”.

nacAuthors: Nicola Rota (Udder health and milk quality consultant).

A specific device for the administration of vaccines against coccidiosis in chickens offer even more

Some time ago, HIPRA took an important strategic decision: to develop and manufacture its own medical devices for the most correct administration of its vaccines. Coccidiosis in chickens is one of HIPRA’s strategic areas where it has recently launched a new and innovative coccidiosis vaccine, EVALON®. For this reason, the development of Hipraspray® was a natural consequence and is now a reality.

In terms of prevention against coccidiosis in chickens, Hipraspray® represents a turning point and a major leap forward in the use of vaccination devices.

With this system, HIPRA offers a high performance vaccination device specifically designed to ensure maximum efficacy of its EVALON® and Hipracox® products. In addition, HIPRA brings benefit to both the hatchery and the final producer.

HIPRA has enhanced its corporate strategy to overcome both current and future challenges. HIPRA is the first company to have digitised the animal health vaccination process, through Smart Vaccination.

In light of the desperate need for parameter optimisation in the livestock farming industry, HIPRA has emerged as the leader in the traceability of vaccination processes.

In this regard, HIPRA deems transparency from hatchery to the end producer to be vital, offering more information concerning the vaccination process against coccidiosis in chickens to all parties involved. This is ensured by software called HIPRAlink®, a platform for tracing, managing and analysing all the data coming from the vaccination process.

With HIPRAlink®, it is possible to trace information such as the doses administered, details of the vaccine batches, details regarding the operation and use of the Hipraspray® device, and to add more information that is of interest to the final producer about the batch of vaccinated chicks.

For a number of years, HIPRA has been strategically tackling the development and production of these devices, which are fully compatible with the characteristics of its products under development.

Biological products –and especially vaccines against coccidiosis in chickens- are extremely complicated to administer, which is why a fully coordinated and parallel approach to both vaccine and device production is vital in order to guarantee the best return on investment for the end customer.

This was achieved by introducing structural changes throughout the company and establishing new departments charged with meeting the needs of customers with highly technical and multidisciplinary requirements.

With a view to generating as much information as possible about the vaccination process and the products used, HIPRA opted to insert RFID chips into the vial labels. The coccidiosis in chickens line of vaccines –EVALON® and HIPRACOX®– was one of the first to carry these chips in the labels.

This has revolutionised the production process and the production lines in particular. This has been achieved thanks to the company’s flexibility, ability to rapidly adapt and the optimism with which it approaches new and exciting challenges.

Combining the worlds of biology, veterinary medicine, engineering and information technology is no easy task. In doing so, HIPRA has enhanced its corporate strategy to overcome both current and future challenges. HIPRA is the first company to have digitised the animal health vaccination process, through Smart Vaccination.

HIPRA’s future looks bright and is full of new challenges in such novel areas as traceability of livestock production processes, the Internet of Things (IoT), Big Data and decision-making, as well as artificial and predictive intelligence in diagnostics, while continuing to offer innovative and exclusive services to its customers.

CHECKING THE MILKING PARLOUR

Everybody knows that to get milk from dairy cattle, the cow has to be milked. Use of milking machines is the easy way to rapidly and efficiently remove the milk without damage to the teat or gland and with minimal risk of the transmission of pathogenic microorganisms that might cause mastitis in cattle.

Go to “mastitisvaccination.com

DESCRIPTION OF THE MILKING PARLOUR

Knowing the milking machine is basic to prevent mastitis in cattle.

The basic milking machine functions are:

• Removal of milk from the cow by vacuum differential.

• The milk then flows to the receiver jar by gravity.

• The milk is pumped from the receiver jar into the bulk tank.

MILKING SYSTEM

The milking system consists of the following parts:

These are the six basic parts of a milking system. In order to avoid the risk of contagious mastitis in cattle, all of them need to be kept under constantly reviewed and they should be replaced if necessary.

• Vacuum pump: The pump removes air and creates the vacuum.

• Vacuum regulator: The vacuum regulator admits atmospheric air in and out of the system to keep the vacuum at a predetermined set level. If the vacuum gets too high, the vacuum regulator will open and let air into the system to lower the vacuum.

• Pulsator: The function of the pulsator is to allow intermittent massage of the teat end to prevent swelling and avoiding possible lessions in the teat that may end up in mastitis in cattle. It does this by alternating between a partial vacuum (milking phase) and atmospheric air pressure (massage phase).

Pulsator ratios of 100%, 50/50, 60/40 and 70/30 are typical ratios. The first number refers to the amount of time the pulsator draws vacuum to open the liner and withdraw milk. The second number indicates the amount of time it admits atmospheric air to collapse the liner and massage the teat. Uniform pulsation milks all 4 quarters simultaneously. Alternate pulsation milks two quarters at a time, while the other 2 quarters rest.

Dual pulsators allow the quarters to be milked at different ratios, such as 60/40 behind and 50/50 in the front quarters.

• Receiver: Milk flows by gravity through the milk line and into the receiver jar. The receiver jar serves as a small holding reservoir until the milk can be pumped into the bulk tank for cooling and storage. The valve between the receiving jar and the milk pump should not admit air.

If a bubbling action occurs in the receiver jar, air is leaking past the valve and it should be corrected or replaced in order to avoid the risk of contagious mastitis in cattle.

• Milking unit: The machine includes teat cups that are in contact with the cow’s teats and remove the milk, a claw where milk pools as it is removed from the four teats, vacuum tubes that provide vacuum to the teat cups and a milk tube that removes milk away from the claw, a source of vacuum for the machine.

Connecting tubes are divided into short milk tube (liner to claw), long milk tube (claw to milkline), short pulse tube (shell to air fork) and long pulse tube (air fork to pulsator).

Content originally created for “the Mastipedia”.

Authors: Nicola Rota (Udder health and milk quality consultant).

ENVIRONMENTAL CONTROL (IV): PREPARING YOUR HERD AGAINST BOVINE MASTITIS DURING LACTATION.

From mastitis vaccination site.

Dry cows are often the forgotten cows, and the environment has huge effects on bovine mastitis. Therefore, prevention of bovine mastitis by environmental bacteria starts with dry cows. You’ll find in this post valuable information regarding the environment in dry cows and regarding how to prepare your herd in order to avoid bovine mastitis infections during lactation.

Dry cow pens are sometimes the forgotten pens, because they do not produce milk.

This is a great mistake, since many new clinical cases that occur during the first 100 days in milk originate in the dry period, as reported in scientific studies.

(Click on the image to go to the original post)

Cases of bovine mastitis infections on the dry period vs on lactation.

Adapted from A. J. Bradley. Vet Clin Food Anim 20. (2004) 547 568.

We can therefore say that prevention of bovine mastitis by environmental bacteria starts with dry cows.

From a milk quality standpoint, we tend to say that new lactation does not start when the cow calves. It starts when that cow is dried off. The highest risk of new infection is just after drying off and around calving, as shown in the graph below, so environmental conditions in dry cows and close up cows must be at least as excellent as for the lactating animals.

Rate of bovine mastitis Infections (Dry Period vs Infection). Adapted from A. J. Bradley. Vet Clin Food Anim 20 (2004) 547 568.

FACILITIES DESIGN

a) Types of facilities

There are three types of facility where the cows can rest:

Tie stall

Free stall

Bedded pack pens

Regardless of the bedding used, design, stocking density and maintenance play a huge role in environmental control of bovine mastitis in this kind of facility.

Remember that we have to provide a clean, dry and comfortable environment for the cows if we want to make them perform correctly. In terms of milk production, but also for control of diseases such as bovine mastitis or lameness.

A poor freestall design will compromise cow comfort and will make it more difficult to keep bedding clean. If freestalls are not comfortable enough, cows will look for another place to lie down, such as in the alleys.

Below right is a design for freestalls:

A poor freestall design will make it more difficult to keep bedding clean and thus, to avoid bovine mastitis infections in dairy cows.

As regards density, for pens with freestalls, the rule of thumb is one freestall per cow in the pen. Despite this, we can find farms working with 2-5% extra cows with no problems. Obviously this situation is not advisable, but we do find it on some farms.

At this point, excellent bedding maintenance is absolutely essential. More than 5% overdensity will lead to environmental problems.

For the bedded pack pens, recommended areas per cow are as follows:

Lactating cows: 10 m2/cow

Dry off cows: 8 m2/cow

Close up cows: 11 m2/cow

Maternity: from 13 to 18 m2/cow

b) Maintenance and Ventilation

These recommended areas are useless if good maintenance and excellent ventilation are not provided. Also, heat stress will play a major role in bovine mastitis if the cows are not distributed evenly along the pen.

When cows suffer heat stress they tend to group in one area of the barn. Usually where the main wind comes into the barn, but sometimes they group in a corner just because they are stressed and they react as some ruminants do in the face of a stressing situation, by grouping. The bedding in these areas becomes very wet and dirty and it became an important source of bacteria that may cause some health problems such as bovine mastitis.

We can see the same situation when we have a great many flies in the barn. Flies are extremely annoying for the cows and must be controlled in order to prevent cows grouping.

Water trough location is also very important. It is common in old facilities to find water troughs inside the bedding areas, producing very wet areas surrounding them, especially in summer time. The areas around water points are also an important source of bacteria.

For freestall pens, water points must be installed in the crossing alleys if a barn has 3 rows of freestalls. These crossing alleys should measure at least 4 to 5 meters in width. For a 2-row barn, the water point must be in the rear alley.

For bedded pens, water points must be out of the resting area, in the alley. Also the rear part of the water point can be protected with a piece of stainless steel so as not wet the resting area.

Correct ventilation is another important issue.

As bacteria need humidity to grow, providing fresh and clean air will reduce the bacterial count of the bedding and the risk of these bacteria to grow and cause some problems like bovine mastitis. Cows will also distribute evenly all along the resting area.

Of course, we must first increase natural ventilation, but also be prepared to install fans when necessary.

TAKE-HOME MESSAGES ABOUT ENVIRONMENTAL CONTROL TO PREVENT BOVINE MASTITIS:

Cows must be clean, dry and comfortable at all times.

Choose the right bedding material. Inorganic materials are always better than organic if we are thinking about milk quality.

Other factors such as availability, price and manure handling facilities will determine one material or another.

Very good maintenance can reduce the effects of bad bedding material. Bad management can destroy the benefits of good bedding material. Proper management is the most important aspect of cows’ bedding.

Cow hygiene is not a choice. It has to be a farmer’s commitment.

Comparison between attenuated and non-attenuated Eimeria vaccines. What is the difference?

Eimeria vaccines for poultry are mainly composed of live oocysts. Concerns about the safety of coccidiosis vaccines have been raised by field users. This study compares the safety parameters of commercial non-attenuated and attenuated Eimeria vaccines with EVALON®, a live attenuated coccidiosis vaccine for breeders and layers.

Most of the Eimeria vaccines available for chickens consist of live parasites that need to undergo two and sometimes three entire life cycles inside the host gut in order to trigger the immune system and subsequently establish a full protective immunity.

On the market, there are live non-attenuated and attenuated vaccines. Live non-attenuated vaccines consist of parasites that still maintain their natural virulence.

(Read more: click below)

http://eimeriaprevention.com/news/safety-of-eimeria-vaccines-against-coccidiosis-in-chickens/

ENVIRONMENTAL CONTROL (III): ORGANIC BEDDING MATERIALS AND ITS EFFECTS ON MASTITIS IN CATTLE.

In previous posts, inorganic bedding materials and its role in mastitis in cattle was reviewed. In this post we will also review the most important organic bedding materials such as straw, sawdust, wood shavings and recycled manure solids as well. We will also give you some take-home messages regarding bedding and its effect on bovine mastitis.

Read more: click on the picture