Milk Quality

Turn Milk Data Into An Early Diagnosis

Tue, 18 Nov 2025 14:23:58 GMT

Modern dairy operations generate an extraordinary amount of information from every milking, yet some of the most valuable health indicators are hiding in plain sight inside the milk meter. For veterinarians, these data streams offer one of the earliest, most reliable windows into emerging disease, often days before clinical signs appear.

“Most people forget about milk production,” says Dr. Aurora Villarroel of Athyr Vet, a dairy herd health consulting company. “The milking machine is actually your best biosensor. It’s your most important one and most people ignore it.”

While different monitoring systems may present data in different ways, interpreting milk yield, component and conductivity data can allow for clinicians to detect subclinical disorders with greater precision than traditional observation alone. As technology becomes more integrated into routine dairy management, the veterinarian’s role increasingly centers on interpreting these numbers, guiding producers toward timely responses and translating these metrics into practical on-farm outcomes.

Milk Yield Deviations

Milk yield is often the first and most sensitive indicator that something is wrong. A cow that deviates from her expected production curve, given lactation history, or a fresh cow whose production isn’t increasing as it should needs to be looked at.

Villarroel advises putting together the milk yield data from a given cow’s lactation history to assist in spotting any irregularities.

“Some of the software will allow you to superimpose all of the lactations of the same cow,” Villarroel says. “What you’re going to see is that the lactations have the same shape. It’s genetic, but it’s a different shape in each cow.”

By comparing the life lactation history of an animal, you can determine whether any observed shifts in milk yield are expected or out of the norm. Villarroel emphasizes the importance of zooming out to get the big picture. When you’re looking closely at two to three days of milking data, small changes in yield may seem insignificant; however, when you put these two to three days into context with a greater portion of the lactation, it may tell a different story.

Component Changes: Fat & Protein

Milk components add critical context to yield changes and help pinpoint specific metabolic disorders. Fat percentage often rises when a cow is metabolizing excessive body fat, making it one of the most consistent indicators of negative energy balance or subclinical ketosis. Conversely, milk protein tends to drop with decreased feed intake, rumen dysfunction or systemic illness. The fat-to-protein ratio (FPR) is particularly useful in transition cow monitoring: an elevated FPR may indicate an energy deficit.

If you’re evaluating whether a new nutrition program is working for your herd, consider using butter fat content and animal activity as indicators.

“The milk yield takes a while still to change, but butter fat and resting time are the first two things that change almost immediately,” Vilarroel says.

Milk Conductivity

Changes in milk conductivity are also useful as an indicator of udder health and useful for the diagnosis of mastitis. Conductivity measures the salt content of the milk, which is dependent on the permeability of blood vessels, or damage to the blood-milk barrier. Because this shift can occur before visible changes in milk or the udder, conductivity is one of the earliest warning signs of mastitis at the quarter level.

“When the conductivity goes up, there’s inflammation in the udder. Something is going on in the udder so that there’s more salt in the milk,” Villarroel explains. “Conductivity changes are a precursor to somatic cell count changes.”

Somatic cell count patterns offer a complementary perspective, highlighting cows that are experiencing subclinical infections. Reviewing somatic cell count trends on a per-cow and per-lactation basis can help identify management decisions that may be affecting udder health.

Put Milk Measurements Together

While each milk metric offers useful information on its own, their real power emerges when they are interpreted together. No single measurement is diagnostic, but patterns across multiple indicators can be used to identify cattle who need to be checked on.

“How do you check every single thing in a cow every single day?” Villarroel says. “Guess what? You can. You just need to know how to interpret it.”

A cow showing modest yield drop may simply be responding to heat stress or social disruption; however, a yield drop paired with an elevated FPR suggests negative energy balance or early ketosis. Similarly, a spike conductivity alone may reflect milking irregularities, but when it appears alongside a somatic cell increase, the probability of mastitis increases.

Transforming milk data into meaningful herd health outcomes requires consistent workflows that integrate monitoring, diagnosis and communication. This may start with a focus on high-risk groups (transition cows, fresh cows, high-somatic cell count repeat offenders) and building structured review protocols around them. At the herd level, data driven insights can shape broader management decisions. Rising conductivity across a pen may indicate bedding or hygiene issues, while recurrent FPR spikes may indicate ration inconsistencies. By combining milk measurements into a cohesive health signal, you can move from reactive case management to proactive herd surveillance — catching problems early when they are the most treatable.

Stop the Summer Surge: How to Keep Your SCC in Check

Mon, 16 Jun 2025 19:51:20 GMT

When temperatures climb and humidity hangs in the air, somatic cell counts (SCC) often follow suit. The added stress of hot weather can weaken a cow’s immune defense, opening the door for mastitis and setting the stage for SCC levels to spike.

While you can’t control the weather, you can take control of the situation. Amber Yutzy, assistant director of animal system programs at Penn State, and Emily Krekelberg, extension educator at the University of Minnesota, share practical strategies to help keep SCC levels in check all summer long.

Heat Stress Headaches
“Somatic cell counts tend to rise with temperature and humidity levels during summer,” Yutzy says. “Environmental stress caused by the high summer temperatures are responsible for the elevated counts. These higher somatic cell counts can stick around on your farm for weeks or months.”

Yutzy explains cows are simply more vulnerable when the heat sets in.

“We often see decreased production during hot weather because cows spend more time standing or lying where it’s cooler and less time eating at the bunk,” she says. “Environmental mastitis also increases during this time because of more frequent exposure of the teat end to bacteria.”

Add stress to the mix, and the immune system takes a hit.

“Research has shown high circulating levels of stress hormones interfere with the ability of the immune system to destroy bacteria. When bacteria enters the udder, the cow’s immune response sends somatic cells to fight back. But stress hormones depress the function of those cells — weakening the defense against mastitis-causing organisms.”

Even only a few problem cows can skew your bulk tank.

“Just a few cows with really high individual SCC can raise the entire bulk tank level,” Krekelberg adds. “Be sure to look at individual cow reports. This can help you pinpoint problem cows and potentially make culling decisions.”

Start with Cultures: Identify the Source
If your SCC is climbing, the first step is to identify the cause. That means culturing.

“Start with a bulk tank culture to find out if the problem is environmental, contagious or something else,” Krekelberg recommends.

Results will guide your strategy, but it’s best to test on multiple days. Sometimes, one aggressive organism overwhelms the plate and hides others. For a clearer picture, consider culturing individual cows with persistent high SCCs or new infections.

When It’s Contagious: Contain and Control
If the culture reveals contagious culprits like Staph aureus, Strep ag, or mycoplasma, you’ll need to implement aggressive containment.

“Contagious cows should always be milked last to avoid spreading the organisms to uninfected cows,” Krekelberg notes.

Krekelberg also advises housing infected cows separately and ensuring proper teat dip coverage, both pre- and post-milking.

“Pre-dip should have a contact time of at least 30 seconds with the teat skin surface,” she says. “Post-dip must fully cover the teat.”

She also stresses not overlooking the basics. Take time to assess how your milking equipment is functioning and review your cow prep protocol with employees. Regular inspections of liners, hoses and vacuum levels are essential to ensure optimal performance and prevent contamination.

When It’s Environmental: Clean, Dry, Repeat
If your issue is environmental, the goal becomes eliminating moisture and bacteria from the cow’s surroundings.

“Add more bedding to stalls or packs and change bedding more often,” Krekelberg suggests. “It could be worth it to bed twice a day if you notice cows are really getting wet and dirty.”

She also stresses keeping milking equipment clean and ensuring spotless teats before unit attachment.

“There should not be any dirt or manure present. Taking the time to clean teats thoroughly makes a huge difference.”

7 Steps to Help Lower Your SCC This Summer
Yutzy, along with British dairy vet Peter Edmondson, a mastitis and milk quality expert and owner of UdderWise Ltd., outline seven tactical steps to improve SCC — especially during high-risk seasons like summer:

Keep bedding clean and dry. Humid summer air encourages bacterial growth. Maintain clean, dry stalls to limit bacterial exposure and encourage cows to lie down in stalls rather than in manure-laden alleys.
Use fans and sprinklers wisely. While cow cooling is crucial, mismanaged fans or sprinklers can backfire by creating wet stalls, overly damp cows or congregation zones that collect manure. Aim to cool cows without compromising cleanliness.
Control flies aggressively. Biting flies are more than just a nuisance —they’re stress-inducing vectors for mastitis-causing bacteria. A solid fly control program protects both herd health and productivity.
Train the team. Reinforce milking protocols with all employees. Proper technique helps limit new infections and ensures early detection of clinical mastitis cases.
Provide plenty of fresh, clean water. At 80°F, cows drink up to 50% more than they do at 40°F. Adequate water access is critical to help them cool themselves through increased respiration and perspiration.
Stop the spread. Create a separate milking group for high-SCC cows and always milk them last. Use gloves and keep them clean. Whether you use paper or cloth towels, one per cow is the rule — no sharing. Replace cloth towels after 500 to 600 uses, and wash at high temperatures.
Make a plan and track it. Edmondson stresses the importance of clear, measurable goals. Focus on cows contributing the most somatic cells to the bulk tank. Consider their history, production and treatment response. Don’t rush to cull. Instead, evaluate carefully with your vet. Most importantly, monitor progress monthly.

Stay Low on Purpose
Keeping somatic cell counts in check through the summer heat takes more than just good intentions. It requires a combination of sound management, consistent routines and close monitoring. By staying proactive and focused on the details, you can limit seasonal setbacks and protect your farm’s milk quality all year long.

“Having a low SCC never happens by accident,” Edmondson concludes. “It’s the result of high intention, sincere effort, intelligent direction and skillful execution.”

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Staph. aureus is being Confirmed More Frequently as the Culprit Contributing to Subclinical Mastitis

Mon, 07 Apr 2025 20:39:06 GMT

If you look hard enough, you can find Staphylococcus aureus (Staph aureus) in at least one cow on every dairy, according to Dr. Justine Britten a PhD animal scientist working at Udder Health Systems Inc .

Despite that bold statement, Britten is not implying every dairy has a mastitis problem or is gearing up for an outbreak. Rather, she is pointing out how common the pathogen is on the farm and that it often flies under the radar, contributing most frequently to subclinical disease.

“One thing I’m still surprised about, is I think that most producers, veterinarians, and consultants know that, and they don’t necessarily,” she tells Dr. Fred Gingrich, Executive Director for the American Association of Bovine Practitioners, during a recent “Have You Herd” podcast: Managing Staph aureus Mastitis in Dairy Cows

Britten says that the prevalence of Staph aureus is increasing, based on the 7,800 bulk milk samples her company tests, on average, each year. From 2017 to 2021, the prevalence stayed relatively flat at about 20%. Today, the prevalence is more than double that.

“We’re seeing it now at around 44% to 45% of all bulk tank samples we do are positive for Staph aureus,” she says.

Consider The Heifer Population

Something Britten says has surprised her is that heifers may calve into a subclinical infection, resulting from Staph aureus, even in a closed herd.

“Being a closed herd will help reduce the chances that’s going to happen, but it’s still possible,” she says.

In evaluating literature, Britten says between 2% and 15% of heifers are going to calve in with it, and they may have a clinical episode. However, cell counts in the infected heifers tend to be low which lessens detection.

“That’s one of the most frustrating things, is that positive heifers may stay around 100,000 or less with their cell count for quite a while before it begins to climb, and that makes it really difficult for producers to get their minds around the fact that this animal is permanently infected with a contagious pathogen. It also makes the disease that much more difficult to manage,” she says.

If the dairy is not proactively screening, heifers typically recover from an episode and look fine. At that point, they are usually returned to the herd where they may infect other heifers and cows.

“My takeaway is if Staph aureus was easier to see, more like a mycoplasma, I suspect producers would be a lot less tolerant of it than they currently are,” she says.

Screen All Cows And Heifers

Britten considers a monthly bulk tank culture as the bare minimum that a dairy can do towards monitoring pathogens in the bulk tank, and she calls it an incredibly helpful tool.

“You’re really operating in a vacuum otherwise,” she says. “Even by monitoring at the bulk tank level, we’re monitoring at the 10,000-foot view. But if [the dairy] is not doing any other culturing, it’s still better than nothing.”

Britten says she is a strong advocate for screening all cows and heifers as that’s the most proactive approach to prevention.

“It works, I know that it works, but it is very important to have some kind of audit system in place, so that you get them all, not 50% of them, not 70% of them, all of them, and that you have a management plan in place for what to do with them,” she says.

On the dairies she works with that have a very low staff positivity rate, they often sell the cows.

“They’re not going to tolerate them, while for others it’s too expensive to do that,” she says. “They’re going to go into a staff pen, or with the heifers, they try and treat them and see if we can get them cleared up. But yeah, screening, culturing of all fresh cows and heifers is the best way to find those animals early and to manage them.”

Take-Home Messages

In the podcast, Gingrich and Britten discuss that in outbreak situations it is important to evaluate why cows are getting infected and remember that cows typically get infected in the parlor and focus efforts there. This includes evaluating teat condition, parlor procedures and equipment function.

Aggressive culturing programs, segregation and culling are important to minimize risk.

Britten provides these three additional take-home points, per the AABP discussion:

Take-home point #1 – Not all Staph aureus colonies exhibit beta-hemolysis, therefore, it is important that all Staph colonies undergo coagulase testing to identify Staph aureus.

Take-home point #2 – Monthly bulk tank cultures are a bare minimum monitoring program for dairy farms.

Take-home point #3 – Somatic cell count is a lagging indicator and cultures will detect infections earlier. Britten emphasized that the difference lies in management practices. Proactive monitoring, culturing, and implementing strict control measures can prevent Staph aureus from becoming a major issue, even though the pathogen is present.

For more information and recommendations, be sure to check out the podcast: Managing Staph aureus Mastitis in Dairy Cows

FDA Says New Round of Tests Prove the U.S. Milk Supply is Safe From H5N1 Virus

Thu, 02 May 2024 13:04:55 GMT

The Food and Drug Administration (FDA) is once again confirming the milk supply is safe with a new round of tests as proof. The latest round of tests come as the U.S. dairy industry continues to battle the outbreak of HPAI H5N1 in cows.

Just days after FDA and USDA confirmed viral material of highly pathogenic avian influenza was found in retail milk samples , FDA says further testing shows pasteurization is killing the virus. A lab at St. Judes Children’s Hospital is taking the genetic material found in the milk and culturing it in live eggs to ensure it didn’t regrow.

According to FDA, the additional testing confirms the safety of the commercial milk supply with what it calls substantial data. The tests were done on 297 samples of milk from 38 states. FDA also tested retail powdered infant formula and says all results were negative.

International Dairy Foods Association (IDFA) tells AgWeb this also confirms the requirement of pasteurization, or heat treatment, of milk in order to move interstate in this country, works in killing all bacteria and viruses.

“The testing that the FDA has continued to release has only cemented that further,” says Matt Herrick, senior vice president of public affairs and communications at IDFA. “The results they received at the end of the week on Friday, determined that the virus was in fact dead. So it would not regrow and would not infect, and pasteurization, at the standard times and temperatures under the federal pasteurized milk ordinance, is effective.”

IDFA also adds more than 99% of all the milk and dairy products in our country are pasteurized.

“And that’s been ongoing for decades and decades,” he says. “And that’s what ensures the safety of our commercial milk supply.”

Related News: USDA Now Requiring Mandatory Testing and Reporting of HPAI in Dairy Cattle as New Data Suggests Virus Outbreak is More Widespread

A week ago Tuesday, the FDA also reassured consumers the pasteurized milk they drink is safe after the agency announced retail milk samples tested positive for fragments of HPAI H5N1. Further testing by a lab at St Jude’s Childrens Hospital showed the virus is not live, which means there is no risk to human health. However, FDA noted additional testing was still being done.

Dr. Richard Webby runs the lab at St. Jude that conducted the testing. He told AgWeb his lab confirmed there is no virus in any of the retail milk samples, but says it was a small sample set they’ve tested so far and more testing is coming. He says even with the limited tests completed so far, his findings show pasteurization is killing the virus.

“It is actually expected that RNA will remain in the milk after pasteurization. Heating (pasteurization) will kill the virus but won’t necessarily destroy the genetic material of the virus (RNA). On its own, the RNA isn’t infectious. It is important to reiterate that the presence of RNA does not mean there is live virus. In contrast, our data says there is no live virus,” Webby told AgWeb.

He says genetic material of the virus, or RNA, is similar to the DNA inside human cells and provides the code to make all of the proteins the virus needs. However, he says while it’s key for influenza viruses, this is different from other viruses in that on its own, the RNA can’t do anything.

“It has to be nicely coated in virus proteins and delivered properly to the inside of a cell. Pasteurization destroys this part,” he explains.

Related News: A Message to the Ag Industry about H5N1

Considering his lab was unsuccessful at regrowing the virus, he says the testing confirmed the RNA in milk is from dead virusses, and therefore, the milk can’t cause any infection.

“In my opinion, based on the small data set we have, yes, the milk is safe,” he says. “I am still consuming it at home.”

Webby points out there is much more researchers still need to learn about HPAI H5N1, especially in cattle. He says influenza in cows is new, and the industry continues to learn as more research is conducted.

In late March, USDA APHIS confirmed the mystery illness that was impacting dairy herds in the Texas Panhandle, New Mexico and Kansas now had a diagnosis: Influenza A. USDA says genetic sequencing revealed it was the same strain of Highly Pathogenic Avian Influenza (HPAI) that’s been in the U.S. for two years. The outbreak has now been confirmed in nine states , however, it’s unclear how many herds it’s impacting.

The CDC claims the outbreak has been confirmed in 36 herds , but testing of retail milk samples last week put that number into question. Viral fragments were found in nearly 40% of the milk samples tested, indicating the outbreak is more widespread that current government reports.

Will the 305-Day Lactation Standard Go the Way of the Dinosaur?

Mon, 23 Oct 2023 12:13:08 GMT

Many of today’s dairy cows are still milking heavily at dry off. In fact, nutritional strategies and commercial products have been developed to help cows diminish milk production and prevent mastitis and other health challenges at the end of lactation.

This begs the question: if a cow is still milking 100 pounds a day after 10 months of lactation, would it be better to allow her to keep milking, if she wasn’t pregnant and due to calve again?

For decades, 305 days of lactation, plus a 60-day dry period, has added up to a dairy cow’s target calving interval of 1 year. But is this a standard that needs to be broken? Dairy researchers worldwide are exploring the possibility of lengthened lactations, based on the realities of modern dairy production.

The topic is explored in a recent article published in the Journal of Animal Science by Dutch researchers from Wageningen University and Research, and another in the journal Animal by researchers at Aarhus University in Denmark. Their shared rationale for longer lactations included:

With fewer calvings, cows would pass less frequently through the transition period of giving birth and freshening, which is considered the riskiest time for cow health.
Sexed semen and genomic selection have allowed for more strategic development of replacement heifers, resulting in the need for fewer surplus calves.
A longer voluntary waiting period (VWP) before rebreeding could potentially improve fertility by allowing them to return to a state positive energy balance upon insemination.
Longer lactations would result in reduction in labor associated with drying off, calving, and disease treatments.

Conversely, the researchers also explored the potential downside of extended lactation. Those factors included low milk production at the end of lactation, and cows becoming over-conditioned prior to calving. On a herd level, another result would be less total meat produced annually, due to fewer calves being born.

Another potential drawback relates to herd-wide genetic progress. If a herd’s highest-producing cows are selected for extended lactation, the contribution of their superior genetics would be reduced because they would be producing fewer offspring. This challenge could be addressed by using advanced reproduction technologies like embryo transfer and ovum pick-up to multiply their genetics more rapidly.

One research-confirmed observation made by both teams was that first-calf heifers have greater lactation persistency compared to multiparous cows. The Danish researchers noted that first-lactation cows promote nutrient partitioning into both milk production and body growth, whereas multiparous cows are done growing.

“This might explain why extending the lactation of primiparous cows seems more advantageous than for multiparous cows,” they noted. The Danish group cited two studies – both examining just single lactations – showing that extended lactation was more advantageous for primiparous cows versus multiparous cows in terms of daily milk yield and economic profitability.

While multiple factors for an individual herd would play into decisions to adopt extended lactations, the researchers discussed three approaches that could be applied to embrace the strategy: (1) adjust the entire herd to a longer calving interval; for example, 18 months; (2) set a longer calving interval for first-calf heifers by delaying their breeding with a longer VWP, while maintaining a standard, 305-day lactation and 12-month calving interval for second-lactation and older cows; and (3) use pre-determined, individual-cow metrics to set optimum breeding dates and lactation lengths for each animal in the herd.

Both the Danish and Dutch papers focused on the limited studies that have been conducted evaluating various factors at play in extended lactation. It is an area of research interest that both teams said requires more in-depth study in the future.

For more on herd health, read:

Cows Will Tell You Whether They're Happy With How They're Milked

Mon, 28 Aug 2023 21:40:28 GMT

Teat end scoring provides Paul Virkler with some valuable insights into a dairy cow’s milking experience.

“In the immediate term, it tells us whether that cow is happy with the way she was milked,” says Virkler, DVM, Department of Population Medicine and Diagnostic Services, Cornell University, Ithaca, N.Y.

In addition, teat end scoring provides Virkler with insights into whether the milking process is harmful to the animal and what needs to be addressed.

“Short-term changes of the teats can prolong the closure of the teat canal after milking and make the cow more susceptible to disease such as environmental mastitis,” he says. “Also, these short-term changes can lead to longer-term changes over time such as hyperkeratosis.”

The Scoring Process

Virkler uses guidelines provided by the Teat Club International (TCI) for the scoring process. TCI recommends scoring a minimum of 80 cows or 20% of a herd, if the herd is larger than 400.

“Make sure you score a haphazard sample of the cows being milked. You want first-lactation animals, older cows, mid-lactation, etc., a good representation of the herd,” he says.

Factors such as hardness, color changes, swelling and abrasions figure into the assessment, which should be done immediately after the milking unit is removed from the animal.

Each teat on the udder should be scored, using a scale of 1 to 4:
1 or Normal – This would be a smooth teat.
2 or Slight Ring – A light ring is visible on the teat but no cracking or keratin fronds.
3 or Rough – The teat end shows a rough ring with some cracking and keratin fronds.
4 or Very Rough – The teat has >4 mm of rough keratosis on the teat end.

When To Score
Dr. Bill Koffman, Dairyland Veterinary Service, Casco, Wis., recommends scoring a milked herd on a quarterly basis.

“Changes in weather, workers and equipment can cause the teat end to change,” he says. “(Scoring) should also be done a week or two after changes have been made to the milking system, procedures have changed or new personnel have been trained. The scores should be saved and compared to ones previously done to get an idea of how the milking process is changing,” he adds.

Koffman wrote an article on assessing teat ends, which is available here: https://bit.ly/3KWSDYn

Virkler says he gets concerned when 20% of the animals in a herd have teat ends showing some level of damage.

“You have to consider the type of damage present. We might accept some firmness issues in the teat ends, for example. But when there are open lesions – cuts and cracks on the teats — the producer needs to take action when that reaches 5% or more. This signals a problem in the herd that needs to be addressed,” he says.

While teat end scoring helps identify a problem exists, the producer and veterinarian still have to investigate the source. It could be a weather issue, equipment (pulsation or vacuum) or a milking management problem leading to low milk flow, or some combination of factors.

“We can collect the data, but the herd veterinarian is critical to interpreting the results and determining what management plan or practices need to be implemented,” Virkler says.

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Managing Mastitis Through Changing Environments

Sat, 19 Aug 2023 11:58:00 GMT

As we have, hopefully, made it through the hottest part of the year, we also hope that SCC and mastitis incidence will decrease along with the temperature. But as we know, mastitis and SCC management are essential all year round. Somatic cell count averages for 2022 were highest in the year’s late fall and winter months. Below are some considerations for managing mastitis as the weather changes.

Record to control

Problems cannot be determined if data is not being reviewed. Evaluate bulk tank, individual cow SCC, and clinical mastitis incidence by season. Look for trends to determine if management SOPs need to be reevaluated during different times of the year. Evaluating historical milk quality data can help plan for the future. Making notes about weather changes can also help determine if management needs to be reevaluated.

The more information we have about a case of mastitis, the more educated decision we can make about mastitis management. Determining the infecting pathogen by sending milk to be cultured or using on-farm culturing provides the most information in guiding milk quality decisions. Keeping a record of contagious and environmental cases can help give more guidance when management decisions need to be made. If most mastitis cases are caused by environmental pathogens, cow and environmental cleanliness need to be the focus of management. An increase in contagious pathogens could indicate problems with milking prep in the parlor. Keep in mind bacteria populations can change throughout the year.

Bacteria thrive in different environments

Do not treat all bugs or mastitis outbreaks the same. With changes in the environment can come changes in bacteria populations on farms. Klebsiella seems to be causing more mastitis cases over the past couple of years, and we mainly see herd outbreaks in the spring. Part of this is because Klebsiella thrives in a wet environment. During winter, when teat skin becomes drier, we may see increased Staph species. Treatment and management of these bacteria types need to be specific depending on the bacteria.

Stick to and refine the basics

When managing mastitis, the basics should be adopted all year round but refined depending on the time of year. The basics should include keeping cows clean and dry, adopting proper milking procedures, using aseptic techniques when administering intramammary infusions, and implementing a mastitis vaccine. Review and make necessary changes to SOPs as changes in the cows’ environment occur.

Can Somatic Cell Counts Get Too Low?

Tue, 17 Jan 2023 14:27:07 GMT

Somatic cell counts (SCC) have long been an indicator of milk quality and udder health. Additionally, processors are willing to pay a premium for milk with lower SCC levels. But can a cow’s SCC get too low? Amber Yutzy, assistant director of animal systems at Pennsylvania State University weighs in.

According to Yutzy, somatic cells are white blood cells that fight infection and repair tissue damage. When the udder is infected, white blood cells move to the udder and into the milk to defend against the invading bacteria. This process is very important; without it, the elimination of even mild cases of mastitis would be very slow, with tissue damage increased.

While lower SCC levels tend to spell higher profitability for dairy farmers, Yutzy notes that some producers fear that cows with significantly low SCC levels may have a compromised immune response to bacteria.

“Ideally, an individual cow cell count should be between 100,000 and 150,000, Yutzy states. “With a count below 50,000, there is some evidence that cows respond more slowly to infection.”

As farms continue to lower their bulk tank SCC below 100,000, they tend to increase the number of low cell count cows in their herd. However, cows with a lower immunity may have an increased risk of clinical mastitis. While the risk of mastitis is elevated, Yutzy does not seem concerned.

“The benefits of having a low SCC far outweigh the risks,” she says. “The answer is not to increase your SCC but to maximize immunity and keep cows in the best environment possible.”

Yutzy goes on to note that low SCC herds usually have low levels of contagious bacteria and limit the spread of that bacteria with good milking procedures and management practices. However, when these herds do get an infection, it is usually environmental. These organisms are opportunistic, not invasive, meaning most animals who get these infections are immune suppressed or stressed, such as dry cows or early lactation animals. Low SCC cows are not more susceptible to environmental organisms, but clinical signs tend to be more visible and grab the attention of producers.

Tips to Keep SCC Low

While individual cows with low SCC levels may have a suppressed immune system, it’s still important to focus on lowering your SCC score. According to the University of Minnesota, there are some simple and practical steps you can take to help lower SCC on your farm. These include:

Looking at individual cow reports - This can help you pinpoint problem cows and potentially make culling decisions.

Controlling contagious infections - Move infected cows to a different area of the barn or into a different pen. Keeping these cows separate is crucial to reducing the spread of contagious organisms.

Controlling environmental infections - Make sure milking equipment is kept clean and spray off any equipment that may get dirty during milking. Taking the time to make sure teats are fully clean will also make a huge difference in the presence of environmental organisms.

Additionally, add more bedding to stalls or packs and change bedding more often. It could be worth it to bed twice a day if you notice cows are getting wet and dirty.

Culturing your milk - Get a sample milk culture to determine what you’re really fighting. Start with a bulk tank culture to find out if the problem is environmental, contagious or something else. The results will narrow down the strategy you should use to combat the issue.

Take bulk tank samples on multiple test days to get the clearest picture of what you’re dealing with. Sometimes one organism can overwhelm the plate so much that other present organisms won’t even show up.
Look for consistent culture results to narrow down the problem.
Consider culturing some cows individually, especially those that consistently have high SCC or have new infections.

For more on milk quality, read:

There’s a New Mastitis-Causing Pathogen in Town: Prototheca Bovis

Wed, 02 Nov 2022 18:48:32 GMT

Prototheca bovis, a non-photosynthetic, yeast-like microalgae, is a mastitis-causing pathogen that has been around since the 1950s. However, it’s prevalence has significantly increased within the last five years, according to Angie Ulness, Senior Territory Manager at Parnell Veterinary Pharmaceuticals.

“Similar to Staph aureus and mycoplasma, Prototheca is hard to detect, has no known cure, and is contagious by intermittently shedding from cow to cow,” Ulness says. “[It] causes incurable acute or chronic mastitis., and there is no easy way to prevent Prototheca infections and no treatment for the mastitis.”

Unfortunately, early symptoms of Prototheca mastitis are hard to detect. According to Ulness, the pathogen thrives in high humidity and plentiful damp organic matter, a common denominator on most dairy operations. Additionally, infections typically develop over the course of several months, indicating its ability to survive or evade host immunity.

“What makes this type of mastitis so dangerous is that often times when a herd is infected, cows show mild signs of inflammation,” Ulness says. “Often times producers do not recognize infection has occurred until the quarter’s nearly dry. To add to the insult, positive cows continue to intermittently shed large numbers of the organism, transferring cow to cow at milking.”

While there is currently no known cure for this form of contagious mastitis, there are steps producers can take to help keep this new and emerging milk quality threat at bay. Ulness provides the following tips:

If you have had a steadily increasing bulk tank somatic cell count (SCC) over time and culture for forms of mastitis, consider also culturing for Prototheca. Identify potentially infected cows for culture that do not respond to antibiotic treatment and monitor SCC data from individual cows.
A producer-veterinarian relationship should be established to help determination of mastitis-causing agents.
Environmental sources should be investigated, gold standard milking procedures and hygiene be practiced, and when infusing the mammary gland wear gloves at dry off and at treatment, and the teats must be clean and dry, using a separate alcohol wipe for each teat before infusing the teat. Do not reuse teat cannulas or tubes and insert the teat cannula only partially into the teat canal.
Prototheca bovis mastitis has shown resistance to a wide variety of pharmacological products, including antibiotics. Because this mastitis is incurable, infected cows should clearly be identified and milked last in the milking order until they can be culled.

For more on milk quality, read:

Feeding Behavior Can Signal Issues with Feed Quality, Management

Mon, 27 Jun 2022 12:36:24 GMT

There’s a story to be told in how cows behave while they’re at the feed bunk. Being aware of what they leave behind, how quickly they eat – and more – can offer insights on the quality, mixing and delivery of their feed, as well as other management factors on the farm.

Luiz Ferraretto, PhD, assistant professor and extension specialist in ruminant nutrition at UW-Madison, explained on the May 25 episode of PDPW’s The Dairy Signal™ that these behaviors can impact a cow’s milk production and overall health.

Dr. Ferraretto and his research team measured several feeding behaviors in second-lactation cows and older: the individual intake of feed in real time, how many times a cow enters the feed bunk and how much time she spends there. From that data, they used historical data to identify trends in intake, behavior and production.

While forage quality and digestibility are key factors in a cow’s capability to convert feed into milk, Dr. Ferraretto shared that more recently, researchers are looking at how physical aspects of forages such as particle size and fragility impact cow behavior while eating.

“When the cow has a diet with too many coarse particles or less digestible fiber she will spend more time at the feed bunk sorting for what she actually wants to eat, or she’ll be eating, but it takes longer for her to masticate and swallow that feed,” he said. “When that happens, she is spending more time to eat less food, and consequently she is not resting and very likely will be producing a little less milk.”

The research also studied how different behaviors of herdmates impact the quantity of diet they consume. Some of their findings were unexpected, including the discovery that a cow’s more-frequent trips to the bunk didn’t always correlate with higher consumption of the ration as compared with herdmates.

“We actually saw the opposite,” said Dr. Ferraretto, noting that a cow was going more often to the bunk in search of a specific diet or she was a less-dominant cow that had been pushed away by others.

Dr. Ferraretto recommends producers watch for several behaviors at feedings:

If cows are changing positions in the feed bunk rather than staying in one place, they could be competing for a spot or sorting for specific parts of the diet they like.
If cows are eating faster than normal, they likely didn’t eat enough the day before or that particular feeding was delayed.
If there are spots across the bunk at which specific feed ingredients have been sorted out, check mixing times and the order of ingredients added to the mixer to prevent individual ration components from separating from the others.

“A good connection between nutritional management, diet and forage production, and cow management is ideal,” said Dr. Ferraretto. “That animal will have a much better opportunity to consume a good diet in the way she wants, then rest and produce more milk.”

In the full episode of “ Feeding Behavior Effects on Lactation Performance ,” Dr. Ferraretto also shares the impacts of stocking density and the barn environment on feeding behavior, including temperature, lighting and air flow. He also offers recommendations for ensuring consistent forage quality and delivery.

All episodes of The Dairy Signal are archived here . Watch The Dairy Signal™ at 12:00-1:00 P.M. CT each Tuesday, Wednesday and Thursday.

About PDPW

Professional Dairy Producers® (PDPW) is the nation’s largest dairy producer-led organization of its kind, focusing on producer professionalism, stakeholder engagement and unified outreach to share ideas, solutions, resources and experiences that help dairy producers succeed.

“She’s A Poor Doer…”

Tue, 29 Jun 2021 14:25:33 GMT

“She just seems broken Doc,” Chris said. “She came in ok, cleaned, milked well for the first 4 or 5 days and now this is her.” I’m standing in Chris’s little red barn of 55 cows looking at a 5-day fresh cow that just isn’t right. She looks depressed, lethargic and has droopy ears. The unfortunate thing is, there’s nothing clinically wrong with her, no metritis, D/A, pneumonia or ketosis. She’s just off.

As dairy caregivers, all too often we see “Poor Doer Syndrome.” These are cattle that struggle for unknown reasons until they subsequently develop an infectious disease, a surgically correctable condition or are culled. Theoretically we “fix” them, but what if I told you that a depressed, lethargic attitude was a sign of a deeper problem; something known as sub-clinical inflammation.

Anyone who has witnessed a birth knows that it is a traumatic event. The female goes through rapid uterine, mammary, and hormonal changes, each of which necessitate significant tissue remodeling. These changes often are caused by sub-clinical inflammation or cause sub-clinical inflammation to onset within the cow This type of inflammation is a natural and necessary process meant to prepare the dam for rearing offspring as well as activate the immune system to fight off common transition diseases.

However, if allowed to occur for a longer duration than physiologically normal, sub-clinical inflammation can alter metabolic functions, inhibit mammary gland development, foster infectious disease onset, and even alter mood. These changes can cause a vicious cycle in which the dam continues to draw more and more energy reserves for the immune system which increases her negative energy balance causing her to mobilize fat from her body reducing body condition score (BCS) and inhibiting the natural clearance of the inflammation. The result of this cycle being a cow that is predisposed to every common transition disease as well as decreasing milk production.

Controlling sub-clinical inflammation is a difficult process and is not standardized If we attempt to mitigate too much inflammation, we risk shutting down the normal processes that transition the cow into lactation, but if we do too little we risk “Poor Doer Syndrome.” Current research suggests the sweet spot lies in the first 2 days of lactation Researchers have found that using a treatment as simple as a standard aspirin dose 2x per day for the first 2 days in milk appears to have significant positive benefits such as reduced somatic cell count, improved 1st service conception, reduced days open, decreased BCS losses and improved milk yields.

With a simple low-cost fix such as this, could we begin to see the death of “Poor Doo’er Syndrome?”

3 Tips to Ward Off Udder Edema

Wed, 21 Apr 2021 19:03:07 GMT

Udder edema: We see it all the time, but how much of a toll does it take on our animals?

Research has shown that nearly two out of every three cows will experience udder edema at least once in their lives, and it’s becoming a growing animal welfare concern, as reported by Cora Okkema and Temple Grandin, both at Colorado State University.

According to a recent Journal of Dairy Science article , udder edema is a noninfectious metabolic disorder that is present in a high percentage of dairy cows. Some of the factors associated with this disorder include genetics, nutrition, oxidative stress and physiological changes in freshening heifers.

Though this metabolic disorder might seem harmless, studies have shown that udder edema can negatively affect the productive life of an animal. Support structures within the udder may begin to break down due to tissue damage, and milk production may be reduced due to fluid buildup in tissue spaces. Risk of secondary diseases, such as mastitis or udder cleft dermatitis, is also increased. In severe cases, damage could lead to premature culling.

While udder edema is a common occurrence on dairies, there are several methods to help prevent it from happening:

Lower Salt Intake

Excessive salt in the diet has been shown to increase the prevalence of udder edema in dairy cattle. To better minimize this, try providing a separate diet for late-gestation heifers to help monitor their anionic salt intake. Different forms of anionic salts include sodium chloride, magnesium sulfate, calcium sulfate, ammonium sulfate, calcium chloride, ammonium chloride and magnesium chloride. Animals who consumed these salts tended to develop edema sooner and took longer to recover. Take time to talk with your nutritionist to help formulate an appropriate diet for your pre-fresh animals.

Reduce Oxidative Stress

Oxidative stress is defined as a disturbance in the balance between the production of reactive oxygen species (free radicals) and antioxidant defenses. It occurs when oxygen is not reduced to water during metabolic processes and can enhanced tissue damage.

To help combat this, be sure exogenous antioxidants such as vitamin E, vitamin C, carotenoids and flavonoids, along with amino acids, are provided in the diet to help prevent oxidative stress from occurring.

Genetic Selection

Unfortunately, some animals are genetically predisposed to udder edema. This especially holds true in higher producing cows. Because udder edema causes deterioration of udder support structures, it may be beneficial to select for improved udder conformation traits to increase the likelihood that an animal recovers from a severe case. Try selecting bulls that are shown to improve udder cleft, udder depth and udder balance.

Though it’s unlikely producers will be able to completely eliminate udder edema from their herd, it can be reduced on a short-term basis by adjusting nutrition and on a long-term basis, possibly, by shifting genetic selection parameters.

Cornell Researchers Explore Stem Cell Therapy for Mastitis

Wed, 11 Nov 2020 02:10:55 GMT

Mastitis is the most expensive disease in the dairy industry. Each clinical case can cost a dairy farmer more than $400 and damages both the cow’s future output as well as her comfort.

Bovine mastitis is typically treated with antibiotics, but with the potential threat of antimicrobial resistance and the disease’s long-term harm to the animal’s teat, researchers at the Cornell University College of Veterinary Medicine are laying the foundation for alternative therapies derived from stem cells.

“Antibiotics can kill the bugs,” said Gerlinde Van de Walle, the Harry M. Zweig Assistant Professor in Equine Health, “but they don’t help with regeneration of the damaged tissue.”

Bovine mastitis damages the cow’s mammary gland tissue when bacteria cause inflammation. The bacteria can enter the cow’s teat when it comes in contact with a contaminated milking machine, a hand or bedding materials. This damaged mammary tissue contributes to milk production losses, quality concerns and increased labor costs.

“Bovine mastitis is the most costly disease in the dairy industry,” said Daryl Nydam, DVM, Ph.D., professor in population medicine and diagnostic sciences. “The second-most-costly is almost not worth mentioning in comparison.”

According to the U.S. Department of Agriculture, 96.9 percent of dairy facilities use antibiotics to treat clinical mastitis cases. While effective against bacteria, antibiotics alone cannot restore the damaged mammary tissue. In their March 16 paper in Scientific Reports, Van de Walle and Nydam explore how the secretions of bovine mammary stem cells can encourage healing and regrowth of damaged tissue as well as rid the mammary gland of harmful bacteria.

“Even after the bug is removed with antibiotic treatment, the milk production will usually not go to its previous highest levels because of that damage to the tissues,” said Van de Walle, lead author on the paper. “That’s where this alternative therapy comes in.”

Van de Walle and Nydam are the first to detail what bovine mammary stem cells secrete. Others have examined the secretome of stem cells from other species, but not bovine. “It’s a brand new area of inquiry,” said Nydam, and it’s led to a host of discoveries.

Their report finds that the secreted factors of these stem cells carry multiple positive effects. They play a role in the formation of new blood vessels and promote the migration of cells, both of which are integral in healing tissue damaged by mastitis. Some secreted factors protect epithelial cells from damage caused by bacterial toxins, and others proved to be antimicrobial peptides that play a role in killing bacteria.

“Besides the tissue regeneration,” Van de Walle said, “it could also help the antibiotics work better, since they produce some of those antibiotic properties.”

The researchers also found that the secreted factors were more effective against toxins produced by gram-negative bacteria, which are generally more resistant to antibodies because of their thicker cell walls. The bacteria that cause bovine mastitis can be either gram-positive or gram-negative.

“FDA-approved intramammary antimicrobials are more effective against gram-positive bacteria,” said Nydam. “So this would be a nice complement to that.”

This paper is part of a concentrated effort for basic and applied science faculty to unite their research practices and address an important disease. Van de Walle’s lab at the Baker Institute for Animal Health performs basic research on viral pathogenesis and stem cell biology, and Nydam is the director of Quality Milk Production Services, a program that addresses milk quality issues for producers, such as disease control and antibiotic use.

“Based on the positive effects of the bovine stem cell secretome we observed in the lab, we now have to take it to next level and test whether it also work in cows with mastitis,” said Van de Walle.

Evaluating the Economics of Adding Management Practices or Products to the Farm

Most of the management practices implemented on the farm are either to manage disease or increase milk production. The market is flooded with products that can help with both goals. Understanding the economics of management practice adoption can make it easier to make adoption decisions.

Determining Disease Costs

Disease costs can be calculated using the simple equation: C = L + E or Costs = Losses + Expenses. Expenses are more straightforward to configure because they include the costs we typically associate with treating the disease, like drugs or added labor. However, preventative expenses are often overlooked. For example, using a pre or post-dip should be considered when evaluating mastitis expenses. Losses can be more challenging to estimate because the costs are not direct. Losses may come in the form of lost milk yield, decreased fertility, or lost milk premiums.

If nothing is done to manage or prevent a disease, the total cost of the disease comes from losses alone. Once a management practice is added, the losses will decrease to a certain point, and expenses will increase. A technical optimum is reached when disease incidence drops to a point where the incidence rate can go no lower regardless of what management practice is added. In that case, expenses are the highest portion of the total disease cost. Often, the economic optimum, the point where we see no financial returns to lowering a disease incidence rate, comes well before the technical optimum.

Marginal Level Milk

The adoption of products or changing management practices to increase milk yield should be evaluated using marginal economics. This means the cost and benefit of increasing milk per pound. Like disease management, a point will come in which the benefit of increased milk yield will not cover the costs. All costs should be considered to make the marginal level milk yield as accurate as possible. For example, feed costs typically increase as milk yield increases, so when determining the potential benefit of adding a product to the farm, feed costs and the costs of the product need to be considered.

Before adopting a product or changing a management practice, try to consider the whole picture. Determine which direct and indirect benefits or drawbacks might occur from management adoption. Overestimating costs of management practices can help ensure that hidden costs may be accounted for.

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