Archive for the ‘Midwest DairyBusiness’ Category

Use necropsies to provide answers to clostridial disease

When a cow or calf dies unexpectedly, you may debate whether to call a veterinarian. A necropsy is the right thing to do, but will it be worth the expense?

The answer is almost always yes, said Dr. Glenn Songer, microbiologist at the University of Arizona.

“My belief is that diagnostic investigation should be a priority, even if you think you know exactly what is going on,” reported Songer to attendees at a Clostridium perfringens Type A symposium during the Western Veterinary Conference in Las Vegas, Nev. “Diagnosis is the only way to know the true cause of death. You need this information to prevent future losses, especially with emerging diseases like C. perfringens Type A infection.”

C. perfringens Type A produces alpha toxin and is implicated in deadly gastrointestinal diseases, such as abomasal ulcers and hemorrhage in calves.  Some speculate that it is involved in the pathogenesis of hemorrhagic bowel syndrome (HBS) in cows.

There is much confusion surrounding C. perfringens Type A, as C. perfringens Type A and Type C cases in calves will look almost identical in histopathology. Diagnostic follow-up work needs to be done in every case.

The first step in obtaining an accurate diagnosis is to call a veterinarian as soon as possible after a death. Samples must be from an animal that died very recently. “The best specimen for necropsy is a typically affected, untreated calf,” said Songer.

An accurate diagnosis also involves good communication. Your veterinarian will submit a field necropsy report along with tissue samples to the diagnostic laboratory. He or she will want a complete history of the case. The diagnostic lab requests information such as the breed, type of operation, age of animal, clinical signs, treatments, if other cases have been observed and if any other diseases are occurring in the herd.

Songer urged producers to be diligent. “Don’t stop with one calf,” said Songer. “Focus on the herd. I know it’s costly, but the answer lies with diagnostics. Losing animals is much more expensive than necropsies and diagnostics. The more animals we look at, the more we learn and the sooner we can control this disease.”

If diagnostic results suggest C. perfringens Type A, Songer recommends developing a management strategy with your veterinarian. For example, HBS cases may be addressed by correcting nutritional and environmental factors that are promoting clostridial overgrowth.

Currently, only one cattle vaccine has demonstrated reasonable expectations of efficacy against alpha toxin. Clostridium Perfringens Type A Toxoid is available under conditional license from Novartis Animal Health US, Inc. The product can be given to pregnant or non-pregnant animals, and has been demonstrated to be safe in calves as young as one month of age.

“Work with your veterinarian to develop a preventive management program,” urged Songer. “You probably won’t eliminate every death, but there are steps you can take to minimize losses. Your veterinarian can help you determine if options like vaccination will work in your operation.”

Novartis Animal Health researches, develops and commercializes leading animal treatments that meet the needs of pet owners, farmers and veterinarians. Headquartered in Basel, Switzerland, Novartis Animal Health conducts business in 40 countries and employs about 2,700 people worldwide. For more information, visit www.livestock.novartis.com.

Emerging clostridial disease targets calves

Clostridium perfringens Type A continues to garner researchers’ attention as a potential emerging pathogen. It’s often associated with severe calf disease, such as abomasitis, with fatality rates varying from 5% to 50%.

“There are as many questions about this disease syndrome as there are answers,” said David Van Metre, DVM, College of Veterinary Sciences, Colorado State University. “It’s a multifactorial disease. No one has found the complete set of factors that cause it.”

C. perfringens Type A is the most commonly isolated infectious agent in abomasitis cases, according to Van Metre, who presented to attendees during a symposium at the Western Veterinary Conference in Las Vegas, Nev.

Abomasitis occurs with an acute onset of gas accumulation in the abomasum. It typically occurs in calves less than two weeks of age. Clinical signs can include rapid progressive bloat and shock, colic, hypersalivation and a distended abdomen. Treatments may include penicillin, antitoxin serum, fluid support, oral adsorbents and oral antibiotics.

“Unfortunately, most calves die acutely,” says Doug Scholz, director of veterinary services for Novartis Animal Health. “Most times, the calf appears fine in the morning. When you come back that evening, you find a dead bloated calf.”

Van Metre recommends focusing prevention measures on enhancing immunity and using feeding practices that inhibit proliferation of C. perfringens in the gut. He recommends:
• Using good colostrum and milk/milk replacer hygiene
• Keeping consistent feeding schedules for dairy calves and maintain consistency in milk/milk replacer composition and temperature
• Avoiding feeding long-stem forage too early
• Whenever possible during severe weather, encourage calves and dams to stand up to limit milk engorgement by the calf after the weather passes
• Making sure animals have adequate copper and selenium status

If you are experiencing significant calf losses, vaccination may be an option to consider. Van Metre shared results of a trial he conducted with Clostridium Perfringens Type A Toxoid in a commercial dairy herd.

The Colorado State University researchers randomly assigned cows and pregnant heifers to a control or vaccinate group. Vaccinates received two doses of Clostridium Perfringens Type A Toxoid in late pregnancy. The study goal was to measure C. perfringens Type A alpha toxin titers in vaccinated dams and the calves fed that colostrum.

“The cows and heifers receiving two doses of the vaccine generated significantly higher antibody titers to alpha toxin one week after the second immunization than did controls,” said Van Metre. “Additionally, the calves ingesting colostrum from vaccinated dams had significantly higher serum neutralizing antibody titers to alpha toxin than calves born to controls.”

Scholz adds that vaccination with Clostridium Perfringens Type A Toxoid is anticipated to work best when you vaccinate the dam and get antibody into the calf through the cow’s colostrum.

“If you are experiencing an outbreak and have significant death loss, you may also want to vaccinate the calf,” advised Scholz. “The important thing is to involve your veterinarian and call as soon as you suspect a problem. If you aren’t tuned in to watch for clinical cases, you will likely be calling for a necropsy rather than a treatment.”

Source: Novartis Animal Health. For more information, visit www.livestock.novartis.com.

Design efficient animal handling facilities

By Ken Bolton, UW-Extension Dairy & Livestock Agent, Jefferson County, Wis

Facilities should be designed to provide cow comfort, worker comfort and labor efficiency. It is very important to check building plans to assure they correctly support the ‘6-flows’: animal flow, people flow, equipment flow, feed flow, manure flow, and air flow. I’ll explore some of the considerations relating to these issues.
One of the main issues in the overall design of a new dairy facility is how milking animals will be sorted, handled and restrained for treatment. Animals need to be examined, vaccinated, artificially inseminated, pregnancy checked, given shots, etc. on a regular basis. The facility design and equipment selection influences work routines, labor requirements and animal stress levels associated with each of these activities. The dairy manager, when making these decisions, is faced with the typical use of capital versus labor trade-off; i.e. “pay me now or pay me later”.
Possible Systems
Most new parlor/freestall operations fall into one of two different types of systems. The “Animal Management Activities” of sorting, restraining and treating are often done in the freestall unit where the animals are housed (home based) or in some special area away from where they are normally housed (treatment area based).
Home based systems utilize self-locking manger stalls where cows lock themselves in place upon returning to a manger full of fresh feed after being milked. The self-locking feature is activated when the animal puts her head in a stanchion to eat. Treatment area based systems use sort gates to separate selected animals from their group as they leave the milking parlor. These sort gates can be manually controlled by the parlor operator or controlled automatically by a computer if animals are identified with electronic identification.
Home based systems
Dairy managers who select the home based system must evaluate the cost of the self-locking manger stall verses the cost of a separate treatment area, plus any labor savings over time. Producers report the following advantages of the home based system:
•    Less traumatic handling of cows since they are treated in familiar surroundings
•    Cows many eat their proper ration while waiting to be treated
•    No time is wasted returning animals to their lot after treatment because they are restrained in their own pen
•    Manger uprights prevent boss-cows from dominating a large section of the feed bunk
•    Large numbers of cows can be automatically restrained saving labor for routine tasks such as tail chalking
•    Manure from restrained animals is handled with normal procedures
•    Locking cows after milking allows teat spincter muscles to close before they lie down, thereby decreasing the possibility of mastitis
•    Parlor efficiency can be improved because flow of animals leaving the parlor does not need to be channeled through a narrow sort lane; and operator time to sort or move animals is avoided.
Among the concerns expressed by some producers is the extra noise generated by some brands of self locking stalls and how to find a specific animal since they are caught and restrained in a random order.

Treatment area based systems
With treatment area based systems, animals are sorted and taken to a special place to be restrained and treated. With this type of system the manager must be concerned with the length of time the animal will be away from its home pen and how it will be returned. Labor requirements, availability of feed and water, the effects of the additional stress placed on animals, plus handling of manure are some of the issues to consider when making this choice.
With treatment area based systems cows are often sorted as they leave the milking parlor. Cows need to be diverted through a narrow alley which allows them to be identified and diverted to a catch lane or catch pen. This animal selection process can be installed anywhere in the path as the animal returns home. If sorting is done manually, it should be done near the rear of the parlor to be easily viewed by the operator, but if automatic sorting is used, it should be located near the end of the return lane to improve cow movement. Producers report the following advantage to the treatment based system:
•    Less traumatic handling of cows since they are treated in a treatment facility versus in areas where the cow should feel most comfortable, i.e. milking, feeding, and resting area.
•    Convenience of having heard health supplies in close proximity to the animals requiring treatment. A herd health facility with attached vet room may also facilitate procedures such as foot trimming and surgery.
•    Only those cows needing attention are restrained versus the entire lot or herd.
•    Lower investment in a head gate and working chute than is required with head locks.

Once cows are sorted, they can be restrained and treated using a chute located in the catch lane, taken to a catch pen containing self-locking stalls or diverted to a palpation station. Palpation stations allow cows to be positioned in a herringbone fashion and restrained as they are given rectal examinations, are bred or given shots. Some producers have installed self-locks in only a portion of each housing area which can be gated off and used to treat groups of animals moved from the sort area. If this technique is used, expect animals to show a preference for eating in the section containing no self-locks.
Another thing to consider with this type of system is that animals returning from the sort areas, after being treated, may use the same traffic lanes as animals being milked. This can cause delays and additional labor to move gates, etc. to prevent mixing of groups.

Conclusion
Knowing how animal management activities will be preformed is very important when designing a parlor/freestall complex. Parlor complexes designed with return lanes on each side of the holding pen work well with home based systems, but not with treatment area based systems because of the need for two sort gates and two catch areas. If a treatment area based system is being designed, it would be wise to consider designing a parlor complex which allowed all animals to return on a single return lane.
Whichever system is selected, it is important to remember that both systems will work, but the effects on management, facility layout, work routines and labor requirements should be taken into consideration. Any additional initial costs should be prorated and added to the on-going labor requirement to arrive at an estimated annual cost of using each system. Putting a value on daily convenience is sometimes difficult, but substantial when considering the building of a structure that will last 10-20 years.
Phone the UW-Extension, Jefferson County Office at 920-674-7196 for more information.

Dairy herd biosecurity teams important

By Ken Bolton, UW-Extension Dairy and Livestock Agent, Jefferson County, Wis

As dairy farms grow, food safety and milk quality has become more of an issue. Concepts of whole herd health are becoming more popular than the approach of treating individual animals. As an alternative, biosecurity plans encompass all areas of milk production directed towards reducing the odds of bringing disease onto the farm as well as minimizing the effects of disease when it does occur.
Carolyn Burns, of Pennsylvania State University, recommends that advisory teams made up of a veterinarian, nutritionist and other dairy advisors help producers define farm goals and develop a biosecurity program. Team members can play a major role in developing good management plans for isolation, traffic control and sanitation. Current farm practices can then be evaluated for weak areas that might pose a problem to biosecurity.
The team will then routinely evaluate records to monitor progress toward achieving farm goals or fine tune areas that need corrective actions. The team should draw a flow chart showing animal movement and identify critical control points for all groups of animals, from the time they arrive on the farm to the time they leave. Precautions need to be established so that all disease hazards posed by adult animals are kept away from newborn calves and young heifers.
Purchased cattle present their own problems when coming onto a farm even with pre-purchase testing. If the farm plans to purchase cows, arrangements for isolation will help protect the new cattle and the established herd from new diseases. The isolation period also allows time to re-test new cows for diseases such as Strep ag., Staph aureus and Mycoplasma mastitis and BVD.
Sanitation is another major area to consider when establishing good management plans. Efforts in keeping housing clean and dry will decrease exposure to organisms that cause disease. Removing sick animals to another pen, separate from fresh cows and other animals, helps to reduce exposure. It is advisable to clean and sanitize these pens after every use. If possible, leave these pens empty for a few days before reusing.
The ideas of biosecurity are fairly simple, but implementing such practices on a routine basis is essential to achieving biosecurity. With the increasing interest in controlling the spread of animal disease, individual farm biosecurity programs are vital to the success of today’s dairy business.
Contact the UW-Extension Jefferson County Office at 920-674-7295 for more information.

Green Meadows Foods & Land O’Lakes Dairy Foods sign milk supply agreement

Green Meadows Foods, LLC and the Dairy Foods-Industrial Division of Land O’Lakes, Inc. have entered into a long-term milk supply agreement, said Sjerp Ysselstein, president of Green Meadows Foods, from the site of
their new manufacturing plant under construction in Hull, Iowa.
“We are excited about our agreement with Land O’Lakes,” said Ysselstein.  This milk will supply our cheese manufacturing capacity set to come online in early November.”
“This agreement affords our dairy cooperative another local outlet for member milk,” said Jim Sleper, director of Milk Supply at Land O’Lakes. “This is a win-win agreement. Green Meadows Foods gains access to a consistent supply of high quality milk, and we gain another market for our dairy members’ milk. This milk supply agreement will primarily affect parts of our current and future milk supply in Iowa, Minnesota and South Dakota.”
Green Meadows Foods, LLC is a new cheese and fractionated whey product
manufacturing facility with a startup capacity to process 2.5 million pounds of milk per day, which includes a master plan design to accomplish an expansion capability to 5.0 million pounds per day in the near future. Geographically poised to absorb the rapidly increasing milk supply of the southern I-29 milk corridor, Green Meadows is positioned for growth and offers a new milk market for the region’s dairy producers.
Initial production from the plant is scheduled for November 2008, the American and Italian cheese varieties will be marketed to Masters Gallery Foods, Inc. of Plymouth, Wis. and the various whey products will be marketed domestically and internationally. “We have been assembling an efficient, state of the art manufacturing facility and are very fortunate to have assembled a highly skilled leadership team of industry professionals to guide the production of quality products for our customers,” said Tim Czmowski, general manager, Green Meadows Foods.

UW-Madison: ‘Real’ Dairy, ‘Real’ Results

University of Wisconsin-Madison dairy scientists and educators are excited about new dairy research facilities. Dairy producers everywhere should see the benefits.

The research projects that had to wait were nerve-wracking enough. But for University of Wisconsin-Madison dairy scientist Lou Armentano, it was the things that never got done that were truly maddening. When Armentano saw the jockeying that went on among dairy scientists for access to the university’s dairy facilities, he knew something better was needed.

A new $5.1 million, 500-cow dairy research facility was constructed at the University of Wisconsin-Madison Arlington agricultural research station.

A new $5.1 million, 500-cow dairy research facility was constructed at the University of Wisconsin-Madison Arlington agricultural research station.

Frustration turned to focus, and the result is a new dairy research facility located at the Arlington agricultural research station. Dedicated and opened in July, the new structure is the product of collaboration between industry and the public sector to expand and modernize the facilities used by UW-Madison dairy researchers.
“We should be able to do a lot more research for about the same amount of money as we were doing with the old facilities,” Armentano said. Some of the gain in efficiency comes from improved use of labor, but there also are efficiencies in research and instruction, yielding results into the future.
With the opening of the new dairy facility, much of the pressure for access to research animals is reduced. The facilities house about 500 dairy cows in two freestall barns.

Research will be conducted in an environment closely matching typical modern dairy operations in Wisconsin. Design was assisted by the Dairy Business Association (DBA) of Wisconsin, under the direction of executive director Laurie Fischer, which created Dairy Building Contractors LLC, hiring DBA member and  dairy producer John Pagel as the lead.

Research will be conducted in an environment closely matching typical modern dairy operations in Wisconsin. Design was assisted by the Dairy Business Association (DBA) of Wisconsin, under the direction of executive director Laurie Fischer, which created Dairy Building Contractors LLC, hiring DBA member and dairy producer John Pagel as the lead.

Research will be conducted in an environment closely matching typical modern dairy operations in Wisconsin. Design was assisted by the Dairy Business Association (DBA) of Wisconsin, under the direction of executive director Laurie Fischer, which created Dairy Building Contractors LLC, hiring DBA member and  dairy producer John Pagel as the lead.
A new, larger milking center connected to the barns offers labor-saving technology. It has the equipment for measuring and monitoring the parameters of the research herd needed for the experiments taking place at the facility.
To  manage cows in groups of eight, the double -16 WestfaliaSurge parallel parlor was split, and is essentially a quadruple-8. It features a new WestfaliaSurge Ear Tag Parlor ID System; Metatron 21 Premium Detacher/Milk Monitoring System; Classic 200 Evolution  milking units, a Vacuum On Demand Frequency Drive System; and a KoolWay 6,400-gallon milk cooling system.
A significant upgrade to capacity is the move to “pen-based” research – a method of managing the research cattle in pens. One of the new barns is fitted with 16 pens, each with the capacity for eight animals. Armentano said the pen system allows researchers to group animals within an experiment in a pen, rather than assign individual animals, increasing control and accuracy of experiments.
“We’ll have the capacity to answer the questions our dairy business community expects us to be able to address,” Armentano said. “We’ll be able to do more with limited resources.”
Ric Grummer, chair of the dairy science department, said the new facility has been designed to mirror conditions of the current dairy industry – and anticipate future changes.
“If you’re looking at what effects a shorter dry period has on a cow it’s not about tie-stalls, freestalls or grazing. The answers are likely to be the same,” said Grummer. “The majority of the hypotheses and objectives of our research are facilities-neutral. But the environment in the new facility is reflective of what the majority of the dairy producers in the state are moving toward.”

(All photos by Wolfgang Hoffmann)

Leaders from the Wisconsin’s dairy industry, state government and the University of Wisconsin-Madison College of Agriculture and Life Sciences (CALS) toasted the opening of a new 500-cow dairy research facility at the Arlington Agricultural Research Station. Pictured are (left to right): state Representative Al Ott, Assembly ag committee chair; Richard Straub, CALS agricultural research stations director; CALS dean Molly Jahn; Alan Fish, UW-Madison associate vice chancellor, facilities planning and management; John Pagel, project consultant and owner of Pagel’s Ponderosa Dairy; Laurie Fischer, executive director, Wisconsin Dairy Business Association; Ric Grummer, UW-Madison department of dairy science chair; and state Rep. Eugene Hahn.

Leaders from the Wisconsin’s dairy industry, state government and the University of Wisconsin-Madison College of Agriculture and Life Sciences (CALS) toasted the opening of a new 500-cow dairy research facility at the Arlington Agricultural Research Station. Pictured are (left to right): state Representative Al Ott, Assembly ag committee chair; Richard Straub, CALS agricultural research stations director; CALS dean Molly Jahn; Alan Fish, UW-Madison associate vice chancellor, facilities planning and management; John Pagel, project consultant and owner of Pagel’s Ponderosa Dairy; Laurie Fischer, executive director, Wisconsin Dairy Business Association; Ric Grummer, UW-Madison department of dairy science chair; and state Rep. Eugene Hahn.

Falling prices: Now what?

Editor’s note: Matt Mattke, Market360® adviser at Stewart-Peterson, is a regular columnist in Midwest DairyBusiness. Contact him via e-mail: mmattke@stewart-peterson.com, phone: 800-334-9779 or visit www.
stewart-peterson.com.

Q: Over the last two months, milk futures have experienced a tremendous price drop, with $20/cwt. replaced with $16/cwt. I have no future milk production sold for 2008 or 2009, but I’m very concerned prices could keep falling into territory that is unprofitable for my business. What should I do?

A: 1. Do not panic and make some emotional marketing decisions you will regret later. At the time of writing this article (Aug. 25), milk prices have already fallen 25% (or about $5/cwt.) from their high, in about a two-month time span. After a price drop of this magnitude, a $1-$3/cwt. correction higher is very possible, and you need to prepare to take advantage of such a rally. It is imperative you do not let any $1-$2/cwt. rally go unrewarded in this market.
2. Any immediate downside price protection strategy you implement should be put options only. These put options will provide you the immediate benefit of a price floor in case prices continue dropping, but give you the ability to participate in higher prices. In the event milk prices do make a $1-$2/cwt. correction higher, you can swap out your put options for forward contracts or sold futures. This will allow you to take advantage of the rally, while improving your price floor above the price level the put options would have provided.
3. Sell into each $1/cwt. rally in 25% increments and focus on contracting out 12 to 15 months of milk production. The milk market is likely in a bear market, and lower trending prices could continue through 2009, so establishing longer-term price protection is important.
Unfortunately, there is no profound strategy that can recreate $19-$20/cwt. milk for your operation. The best decisions you can make at this time are to get downside protection in place in a manner that leaves your upside open, and then roll that protection up on a rally. Price corrections higher in an overall down trending market can be quick and sharp, so it is important you get your marketing strategy in place and watch this market extremely close. Opportunities will come and go quickly, and a quick upward correction to $18/cwt. milk could end up lasting only part of a day. If you do not have the time to keep up with this volatile milk market, consider delegating the task either to someone else in your operation or an outside professional.
FYI
■ To have your marketing questions answered in this column, contact Matt Mattke, Market360® adviser at Stewart-Peterson. Contact him via e-mail: mmattke@stewart-peterson.com, phone: 800-334-9779 or visit www.
stewart-peterson.com.

Maximize cull cow value when production wanes

By Glenda Flora

When it comes to maximizing asset value, dairy producers share some principles with other businesses.
For example, a dairy producer can empathize with someone with a pizza business who faces the challenge of maintaining delivery vehicles. Despite best efforts, including changing oil and fixing dents, the vehicles eventually begin to wear out –- some sooner than others. It becomes a balancing act, footing expensive repair bills and taking into consideration each vehicle’s trade-in value.
Dairy producers get better every year at keeping animals healthy and productive, while increasing their efficiency and productivity. But maximizing the cow as an asset includes making sure that when its milk production potential wanes, the cull value is as great as it can be.
Unfortunately, some producers don’t recognize this value, and many certainly don’t maximize it. Every cow will someday become a cull cow. And a few otherwise good producers are neglecting some fairly simple steps to assure a cull cow’s highest sale value.
In the past, producers have accepted the premise that they get little value out of a cull animal. Some view any steps to maximize the cull’s value as wasted, since those steps probably aren’t going to pay off at the sale barn.
But there’s no reason a dairy producer should accept less for their culls than what they are worth. It’s becoming increasingly evident extra value can be obtained for very little additional effort.
The meat from cull cows is no longer just used for ground beef. About 44% of the muscle from cull dairy animals is used as whole muscle cuts. Protecting the integrity of those cuts is more important.
Injection site blemishes in whole muscle cuts lower the value of cull cow carcasses up to $70 each, according to the 1999 National Market Cow and Bull Quality Audit. The audit, which was paid for through thee $1/head Beef Checkoff Program, found 4.2% of all dairy cows showed injection site knots in the round. Making injections subcutaneously in proper locations, away from the round and sirloin, costs no more to do, yet can improve the animal’s value.

Keep them moving
Earlier culling also pays dividends. Cull cows need to be in good condition when they get to the slaughter plant –- especially since downer cows are not accepted for human beef production. Not waiting until the last minute can be the difference between an animal that’s an asset and or one that’s an extra cost.
Proper use of antibiotics prior to harvesting is also important. Antibiotic testing for meat is sometimes more sensitive than for milk, because a cow’s kidneys will hold antibiotics longer. Treatment decisions for sick cows should be made with care – and with plenty of withdrawal time.
One approach is to feed cull cows for a period of time before selling them. The time allows antibiotics that may be still be in the system to be eliminated, while putting additional weight on the animals. Not all producers have the space, labor or facilities to feed cull cows, but in small tests where inexpensive feeds have been used, it has proven profitable.
Producers will find management decisions for cull animals entering their declining years do pay. It isn’t possible to put a precise value on some of the efforts, but no one can deny preventing lameness and utilizing good injection techniques won’t pay off for producers and the dairy industry.
We all want to do the right thing. Dairy producers do it in their milk quality assurance programs. We must look to our beef quality assurance efforts, too. It’s in our own best interests.
FYI
■ Glenda Flora, along with her husband Sam and seven children, owns and operates The Bar F Cattle Co,. Quinter, Kan. The enterprise includes a 100-cowd dairy, a dairy calf growing operation and 200 head of commercial beef cows. She is a member of the Cattlemen’s Beef Board, currently serving as chair of the advertising. She is also a member of the Kansas Cattle Women, American National CattleWomen, American Angus Association, American Red Angus Association and Kansas Farm Bureau.

Johne’s Control

Johne’s disease remains one of dairy’s biggest herd health challenges.

By Phil Durst & Dan Grooms

Top scientists from around the country shared Johne’s disease research results at a three-day conference at Michigan State University earlier this year. In addition, a single-day educational conference, “New Horizons in Johne’s Disease Control: Integrating Cutting Edge Research into On-Farm Practice” was held to review practical on-farm applications. Following are summaries of some of the presentations.

Best Management Practices for Control of Johne’s Disease, by Scott Wells and C. Ferrouillet, University of Minnesota.

To assess how commercial dairy producers implemented recommended Johne’s disease control practices, the authors asked producers:

• “How effective are these practices for the control of Johne’s disease?”

• “What are the best control strategies for use in dairy herds?”

They found that while testing and culling of Johne’s-positive cattle and, in some states, vaccination, have their place, management to protect vulnerable calves from exposure to Johne’s-causing bacteria is the most important tool to control the disease.

As in Michigan, Minnesota has been involved with a herd demonstration project for five years. Six Minnesota herds completed a risk assessment at the start of the project, and herd owners determined which control practices they would implement. Annual testing, using both serum ELISA and fecal culture, measured progress. Over the five years of the study, the prevalence of Johne’s disease within the herds decreased from 8% down to 3.1% of cows (using serum ELISA) and from 10% down to 5.6% of cows (using fecal culture).

In addition, surveys of Minnesota producers enrolled in the Minnesota Voluntary Johne’s Disease Control Program showed these producers effectively reduced their Johne’s risk scores (years 1 & 2) and prevalence of cattle testing Johne’s positive (years 1-4) by changing management practices, but risk scores and prevalence of infected animals leveled off thereafter. They concluded that implementing risk control practices (see box for a list of some recommended practices) reduces the rate of Johne’s disease within herds by reducing the number of new infections.

However, even over a five-year period, the disease was not eradicated in any of the herds. It will take more time and a continued commitment to maintain tight Johne’s disease control practices, including ceasing purchase of cattle from herds of unknown Johne’s status, to eliminate the disease.

Consensus Recommendations on Diagnostic Testing for Johne’s Disease (paratuberculosis) in the U.S., by Michael Collins, University of Wisconsin.

A team of experienced Johne’s disease veterinarians set out to define the best course of action regarding Johne’s disease testing in dairy and beef herds based on business type, infection status and prevalence.

The team acknowledged that producers should focus on management as the primary means of Johne’s disease control, with testing used as a secondary tool.

They looked at available testing options based on the accepted sensitivity and specificity of each test, as well as the purpose of the test, including: classifying a herd as infected; controlling the disease; surveillance; eradication; and confirming the disease in herds with no prior confirmed Johne’s disease cases and in herds that are known to be infected. Because each test has strengths and weaknesses, test selection should be based on the objectives of the testing. Considerations included:

Only low-cost tests are sellable to producers.

Speed of test results is over-rated. More important is having the results at the time when the producer needs to make a decision about culling or classifying an animal as “do not breed.”

• Look at every test result quantitatively, considering the state of disease progression may be determined by response to a test.

The authors prepared a table with recommendations for commercial dairy herds, seedstock dairy herds, cow-calf beef herds and seedstock beef herds. For instance, the recommended test to classify a commercial dairy herd as infected is a pooled environmental culture, whereas the recommended test to control disease in the same herd is the ELISA. To confirm a clinical diagnosis of Johne’s disease in a herd with no prior confirmed cases, they recommend a necropsy of animals that die or can be sacrificed, or fecal culture or polymerase chain reaction testing of others.

The full table and explanation is included in the proceedings at www.jdip.org.

MAP Super-shedders: A New Paradigm Shift in Johne’s Disease, by Robert Whitlock, University of Pennsylvania.

Having previously defined Johne’s diseaseinfected cows that are “super shedders” of the bacteria, and knowing that the risk of exposure to bacteria by herdmates on the farm is high, a team working with Dr. Whitlock tested the hypothesis that some cows may ingest the bacteria Mycobacterium avium paratuberculosis (MAP) and subsequently excrete it without becoming infected. By excreting the bacteria as pass-through bacteria, they risk being identified as infected animals when they, according to the hypothesis, are only passive shedders of the organism.

To test their hypothesis, they tested almost 2,300 fecal cultures from 556 cows in three herds in three states. Seventy-eight of those cows were culture positive, for an apparent prevalence rate of 3.5%. Bacteria in cultures from manure samples are measured as colony forming units (cfu) of MAP per gram (gm) of fecal material. Low shedders may have 5 cfu/ gm of manure; moderate shedders may have 50 cfu/gm; and heavy shedders may have 500 cfu/gm. Super-shedders are defined as shedding 10,000 to 10 million MAP bacteria per gram of manure.

In these three herds with a fairly low apparent prevalence of Johne’s disease, 15 cows (some from each herd) of the 78 culture positive cows (19%) were defined as super shedders. A single super-shedder cow puts out bacteria approximately equivalent to seven clinical cases or 160 heavy shedders, or over 2,000 moderate shedders or almost 24,000 low shedders.

These cows account for tremendous numbers of bacteria in the animal’s environment and, although few in number, put many other animals at risk of infection. Therefore, identifying and eliminating super shedders is important in controlling the transmission of Johne’s disease.

Diagnostics and Strain Differentiation of Mycobacterium avium paratuberculosis: Current Tools and Challenges, by Srinand Sreevatsan. University of Minnesota.

The current tests for Johne’s disease are valuable, but limited in sensitivity, the ability to detect subclinically infected animals, determining the stage of the disease and to specifically identify differences in the strain of the disease-causing bacteria.

However, scientific advances, including the recent characterization of the complete genome sequence of a cattle isolate of MAP allow researchers to continue to seek ways to overcome those limitations with new tests and new means of identification.

The immune reaction within an animal in response to an infection has a progression that is well-defined. Research is being conducted to identify bio-markers to help pinpoint the state of the disease.

Bio-markers also may in the development of therapeutics, determining response to therapy and predicting prognosis.

Happy Birthday, Afact

With the backdrop of higher food and energy prices and concerns about future food production capabilities, the American Farmers for the Advancement and Conservation of Technology (AFACT) held its first AFACT Summit in Chicago. From its embryonic start as “Voices for Choices,” a campaign initiated by DairyBusiness Communications, to its official birth just a year ago, the organization now boasts 1,000 dairy producer members who do not take kindly to attacks and restrictions on science and technology in the production of milk and other food. They represent about 1.5 million U.S. cows. There are another 400 members in related farming or agricultural enterprises. AFACT leaders contributed more than $125,000 out of their own pockets to get the organization on its feet, because they believe strongly in their cause.

July’s AFACT Summit brought together regional and national leaders of ag companies with similar interests in preserving access to modern agricultural technologies. The meeting’s main theme was to emphasize how producer advocacy can help reconnect with food retailers and consumers to educate about and protect the use of those technologies, promoting not only the efficiencies of modern agriculture to feed a growing world population, but also to share their passion and values in their pursuit of sustainable and environmentally sound food production.

AFACT is young and, like everyone, must admit to some youthful mistakes. Some early actions were based solely on emotions, after having been backed into a corner by those with far different agendas and motives. But they have learned quickly, and are mature beyond the single candle on their birthday cake.

This is truly a “modern” organization, in that most members have never met. Nearly all business is conducted electronically, in almost weekly teleconferences and daily e-mail communications. They’re using that same electronic technology to combat anti-animal agriculture/ technology activists – and having success (ask them about the Wal-Mart blog site). They also strive to make communication personal, by visiting one-on-one with grocery store managers to discuss marketing practices, and conducting consumer focus groups to find out what consumers “really” think about milk label absence claims. They’ve spent a great deal of time learning about the tactics and methods of those opposed to animal agriculture and technological advances, and refuse to concede the moral “high ground” to them. And, even though many have never met, AFACT leaders have developed a cohesive team with shared passions and values.

They’re also getting more arrows in their quiver. Studies in Europe, at Cornell University and South Dakota State/University of Minnesota (see page 20) show modern, efficient dairies have a smaller carbon footprint per unit of food produced, despite claims to the contrary. A milk composition study compiled at Penn State University showed that despite marketing claims and milk labels, there’s little or no difference in the composition of milk produced conventionally, as “rbST-free” or organically (see page 23). In its early stages, AFACT asked the American Farm Bureau Federation to monitor retail milk prices for regular, “rbST-free” and organic milk.” Those numbers show profits are going somewhere, and it’s not back to producers – many of whom are forced to give up tools which could boost their bottom line.

If you’d like to wish AFACT a “Happy Birthday,” or join its growing organization, visit www.itisafact.org. The group, like cheddar, will get even better with age.

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