The most recent report of highly pathogenic avian influenza (HPAI) has resulted in the depopulation of 1.8 million head of poultry at a commercial table egg facility in Weld County, Colorado. Colorado State Veterinarian Dr. Maggie Baldwin said the state’s dairies and poultry facilities have cooperated with her office diligently to reduce the spread of HPAI.

Baldwin said the monitoring, testing and reporting of HPAI in Colorado is a result of the cooperation between producers and partners, including the State Veterinarian’s office and is important to reduce the spread between dairies and poultry facilities.

“Do I think Colorado has the most cases in the nation? No. Do I think Colorado has the most reported cases in the nation? Yes. Absolutely,” Baldwin said.

When HPAI was initially detected in Texas several years ago, Baldwin said her office began working and meeting with industry partners to communicate information and to demystify the process if and when HPAI is reported, and to assure producers the office will support the producer through the process.

Baldwin said just short of enclosing farms beneath glass domes, Colorado poultry and pork producers are using every biosecurity tool in the toolbox. There are, she said, varying levels of biosecurity that agriculture producers may incorporate depending upon the risk presented with the ultimate goal of preventing disease introduction.

In poultry, she said preventing HPAI and virulent Newcastle disease are high priorities as far as foreign animal diseases. Domestic animal diseases are also a priority as they can affect animal health and welfare.

BIOSECURITY MEASURES

Baldwin said some of the state’s poultry producers have full shower in/shower out facilities with site specific clothing and boots as well as truck washes for vehicles or equipment entering the facility. Another level of biosecurity, she said, often includes site specific coveralls and boots with some facilities with numerous barns implementing barn-specific coveralls and boots to prevent the spread of disease from one building to another.

“There are all sorts of different levels our producers can implement,” she said. “Whatever works best on that facility when looking at all of the different movements on and off of the farms. That’s everything from visitors and regular personnel to vehicles and equipment and trash service and all kinds of things that have to come on and off every day. It’s really doing a full assessment of the risk that a person or vehicle might bring on the farm.

She said feed is complicated as a vector of disease. One of the significant challenges facing vertically integrated facilities like pork and poultry are shared feed mills and shared feed trucks. Some farms have on-site feed mills, resulting in a relatively closed system with biosecurity measures for trucking ration ingredients into the site.

“Having shared feed mills is a risk factor and that is one of the things they assessed in the 2014-2015 HPAI outbreak where we saw, in the Midwest especially, a lot of shared feed mills and other things that had become infected,” she said. “That’s something the industry has really studied.”

Baldwin said in the past two years, she has seen spillover of HPAI from wild birds into poultry facilities but the dairy event is completely separate and not carried and shed by wild birds. The initial introduction into dairies was one single spillover event by wild birds into dairy farms.

“All of the subsequent spread of this disease has been direct and indirect contact from dairy farm to dairy farm,” she said. “Now, the risk we have is much greater for our poultry industry because we have a virus that is spreading from mammal to mammal, from cow to cow, from dairy to dairy and now we have so much of it in the northeast part of the state that it is posing a significant risk to our poultry farms.”

In diary cows, the earliest indicator of HPAI is decreased rumination in farms with individual animal monitoring systems.

“In fact, in one of our herds, they thought their rumen-monitoring system was broken because so many that decreased at the same time,” she said.

Infected cows are going off feed and exhibit significantly decreased milk production, with a thick, colostrum-like consistency. One herd, she said, reported a 30% decrease in milk production.

“The good news is that pasteurization is effective,” she said. “The pasteurized milk ordinance just celebrated its 100^th year of being in place and pasteurization is still effective for disease control.”

Baldwin said increased mortality is the earliest indicator of HPAI on an infected poultry farm. The farm in Weld County currently undergoing depopulation notified the state veterinarian’s office on the first day of elevated mortality and she said that early reporting was helpful.

MONITORING TOOLS

Some poultry farms with monitoring tools also report decreased feed and water consumption and decreased egg production. Baldwin said it is a systemic disease and symptoms can present in multiple different ways.

Affected birds are destroyed and don’t enter commerce. Eggs laid greater than 48 hours prior to clinical signs that had already been sanitized and packaged may enter commerce or even be sent to a pasteurizer for liquid eggs. None of those eggs, she said, have risk for the virus.

Baldwin said early reporting is important to allow her office to help put into place measures to prevent further spread of disease.

“On the dairy side, if we can know that these facilities are infected early on, they can put measures in place to decrease the amount of time they’ll be clinical and decrease their production impacts,” she said.

On the poultry side, she said early reporting is critically important because the producers only receive indemnity compensation after the disease is reported. Early intervention also, of course, reduces the risk to animal wellness and welfare.

Baldwin said the production impacts are significant and each affected facility is assigned a case worker veterinarian who works with the dairy’s herd veterinarian. Wyoming’s Office of the State Veterinarian also sent veterinarians to assist with some case management duties.

“We’re having better compliance because we have worked hard on the why,” she said. “Not only why is important that they monitor closely, but why is it important that they report. The why isn’t because it’s a rule or requirement, that’s not the why. The why is because we want to be good neighbors and good partners in disease response, and we don’t want to see anyone else go through this.”