Two steps forward and one step back might best describe the progress the dairy industry has made to address the issue of lameness in the U.S. cowherd. While progress has been made, the problem is still too prevalent, according to Nigel Cook, professor of food animal production medicine at the University of Wisconsin.
“If you talk about physical well-being, I think lameness and hock injuries are the No. 1 and No. 2 issues on the farm (in that order),” he says.
Cook says the issue of lameness specifically is under-reported on dairy farms, as producers underestimate the prevalence of it and tend to overlook those cows that are mildly lame. Based on research and experience, he estimates about 22% of U.S. dairy cows walk around the farm with a noticeable limp.
“I think that’s something we really need to do something about,” he told Fred Gingrich, DVM and Executive Director of the American Association of Bovine Practitioners (AABP), during a recent “Have You Herd?” podcast.
Cook says when he and his team do welfare audits and lameness assessments, the farmer is often focused on the animal unable to bear weight, while he and his team will look for any animal that has weight-transfer challenges or pain associated with their limbs.
“I think that’s where a sort of disconnect comes into play; the farmer thinks their lameness issue is under 5%, while when we go out and look it’s often 25%,” Cook says.
Even mild pain that cows experience with lameness impacts milk production, health and well-being. In addition, lameness can change the structure of a cow’s hoof and increase the risk of further lameness incidents in the future.
Lameness Is A Costly Issue
Penn State Extension has calculated the cost of lameness and shared that information in an online article: Lameness: It’s Costing You
Researchers (Dolecheck and Bewley, 2018) estimated that lameness can cost between $76 and $533 per case, in 2023 dollars.
A study published in the April 2023 edition of the Journal of Dairy Science (Robscis et al., 2023) investigated the economic impacts of lameness in dairy herds. The model used in this study considered reproductive status, milk production, parity, stage of lactation, and interaction with other diseases. This model also considered whether the cow was newly or chronically lame.
When considering how much lameness costs a farmer, Robscis et al. (2023) included a loss in milk production, changes in reproduction, and treatment costs. This study suggested that it costs an average of $336.91 per case of lameness.
Digital dermatitis was the largest cause of lameness and cost almost $100 more than other causes of lameness, the Penn State article reports. For each additional week that a cow remained lame, it cost the farmer $13.26 more per week.
Lameness Affects Routine Cow Behavior
Cook says the three issues most often contributing to lameness are digital dermatitis, white line disease and sole ulcers, Cook says. On larger dairies, another issue he would add to the list is thin soles.
“As we walk cows on concrete, sometimes up to a half mile a day, it basically wears the sole away. Those thin soles can be associated with lesions in the toe, what we call toe ulcers,” he explains.
Cook told Gingrich that concrete has a low coefficient of friction, meaning less force is needed on the surface of concrete for slipping to occur. “So as the cow starts and stops, they tend to slide. Concrete doesn’t have a supporting structure like the cow has on pasture.”
Once a cow becomes lame, she behaves differently because of the pain she feels in her legs and/or hooves. Depending on pain severity, the cow can get stuck in a lying down position when she wants to stand, and she can get stuck standing when she wants to lie down.
“It’s that transition from standing to lying and then lying to standing that they really have trouble with,” Cook says.
Putting down rubber isn’t a cure-all for flooring issues, either. While it can reduce contusions to soft tissue and pressure on the foot, it can increase the risk for sole hemorrhage and sole ulcers.
“The best flooring surface is one that a cow doesn’t stand on for half the day, and that means getting her in the stall and resting because that reduces pressure,” Cook says. “Once we’ve got the stall surface set, the design of the stall, a comfortable place to lie down, you can put rubber wherever you like after that, but get the lying space fixed first.”
Cook says he sees barns that have large quantities of concrete flooring, but that it works OK because the farmer has done a good job of providing stall comfort. “Then, strategically, you can use rubber in places where we force cows to stand, such as in the parlor and the holding area.
Evaluate Cow Lying Time
Lying time is a major factor in preventing lameness, improving cow comfort and returning lame cows to soundness. The amount of lying time a cow has is a good clue to whether the dairy is allowing her to have optimized resting behavior.
“That’s basically the notion that cows get to lie down when they want to,” Cook says. “It’s not necessarily just hours a day. It’s that sort of freedom to choose a place to rest and then get adequate rest on that given day.”
There are some correlations between the amount of time the cow spends lying down, resting, and the amount of lameness that occurs or whether it occurs.
“The first is animals get lame from spending too long a time standing, putting too much load on the suspensory apparatus of the claw and creating things like sole hemorrhage and sole ulceration because of that increased loading,” Cook says. “What we know now is once a cow has those structural changes (in the hoof) they’re permanent, and that can put those animals at risk of repeated episodes of lameness.”
Through research, Cook was also able to determine that reduced lying time in early lactation is a risk factor for core lesions that occur later in lactation. “It took us some time, but there are some really key, pivotal studies that elegantly show that,” he says.
Overstocking Has Long-Term Consequences
Cook encourages dairy producers to look for balance in how much time cows spend in and out of stalls.
“We want the cow to spend no more than three to three-and-a-half hours a day out of the pen,” Cook says. “Otherwise, we compromise the ability of the cow to access the stall and rest for 11.5 to 12.5 hours a day, which we think is somewhat normal in a freestall environment.”
He adds that when he assesses farms that are having lameness issues, he often finds scenarios where the cow is spending five or six hours a day out of the stall due to over-stocking.
“We commonly go into herds that have 1.3, 1.5 cows per stall and while many farmers can manage their herds amazingly well at those high stocking rates, you are compromising lying time and that will catch up with you eventually,” he explains.
Another common issue is when the dairy producer is using stalls that weren’t designed for the current cow size, or if there’s a lack of manpower needed for adequate turn times.
“I’ll just add if you’ve got a robot, you don’t get let off the hook there, because we found in free-flow herds, there are subordinate animals that struggle to access the robot,” Cook says. “They get out-competed at the swing gate and they can be waiting for four or five, six hours a day to milk, even in a robot facility. So that’s another area where we find rest compromised.”
Cook and Gingrich encourage dairy veterinarians to be involved in lameness prevention and improving cow comfort on the farm by performing lameness audits and reviewing hoof trim records. They recommend using a time-lapse camera to help in the process of monitoring cow behavior, insights that farmers can then see for themselves. Time-lapse cameras are available on Amazon with a starting price point of $150.
Cow-attached sensors or accelerometers can also measure lying behavior and activity when attached to the leg and can track rumination and eating when attached to the neck, Penn State Extension reports. These types of sensors are also widely used for heat detection. Learn more at Impacts of Lameness – Preventing Lame Cows
Maximize Stall Comfort
Stall surface plays a significant role in the ability of the compromised cow to transition between standing and lying down. Good cushioning, traction and support allow the animal to stand or lie down and rest normally.
Cook is a proponent of using deep sand bedding in stalls. “It’s associated with about a 40% reduction in lameness, largely because it helps optimize resting behavior,” he says. “It’s also a better, more attractive surface in the alleyways, and maybe reduces the risk for white line.”
During their discussion, Gingrich recalled one time when Cook had told him that banning mattresses would have a significant, positive impact on improving cow welfare.
“That might have been said a little tongue in cheek, but it’s probably true,” Cook told Gingrich.
While Cook says he has worked with herds on mattresses that have low levels of lameness, it’s usually thanks to a proactive manager who identifies lameness issues quickly and gets cows treated.
Cook reiterated that he believes the gold standard for providing cushioning for cows is a deep bed of sand. The sand conforms to a cow’s bony features and reduces the potential for hock injuries when she changes position.
“When she chooses to get up and down, she’s got that cushion, traction and support to be able to do that even in a situation where she’s compromised and has a sore foot,” Cook says.
Gingrich saw similar benefits when he was in private practice.
“My producers that constructed new barns or remodeled their stalls, and converted to sand, they pretty much all have said their major problems seem to go away,” Gingrich recalls. “Mastitis in milk quality improved, production improved more consistently, lameness, as you said, significantly decreased, even culling was reduced. We just had fewer broken cows.”
Additional Bedding Considerations
While Cook likes using sand in stalls, he notes it does have some limitations and can pose challenges, too. “I readily admit sand gets everywhere and can hurt manure pumps and various other things,” he says.
The new kid on the block that some dairy farmers are evaluating is the use of a deep bed of recycled manure solids. But it has drawbacks to consider, as well.
“When you’re dealing with an organic compound versus an inert, inorganic compound, you have potential for bacterial growth issues,” Cook says.
Notes Gingrich: “We want to improve cow comfort, but we don’t want to create another problem with our bedding type, in the process.”
“I think one of the lessons learned is it’s got to be drier than the material that comes out of the screw press,” Cook adds. “And that means using some kind of a supplemental drying process that takes us to, in our climate here, about 50% dry matter. That percentage of dry material seems to behave a whole lot better than the 70% moisture, 60% moisture material that comes out of screw presses.”
Stall dimensions that allow cow movement are another important consideration for producers to consider as they address lameness. Cook says cows need enough room to “lunge and bob.” Essentially, they need freedom of movement in a space so they aren’t restricted, but he adds that having the freedom to move needs to be balanced with the need to keep cows clean.
Don’t Overlook Environmental Stresses
Cook says when he first started his career, he thought if he could create the perfect stall the cow would lie down even in overly warm conditions. That was not the case. Instead, what he learned was that good ventilation and the ability of a cow to be cool in hot weather conditions is critical.
“Even in a good environment or circumstance, when heat comes along heat-stressed cows end up standing for protracted periods of time,” he explains.
Cook encourages dairy producers when they’re building barns or remodeling facilities to focus more on the cow and less on how they will handle manure or implement other processes.
“Focus on the cow,” he says. “That’s the big thing. Cow comfort is that important.”
Gingrich advises producers and veterinarians to visit other dairy farmers to learn what works for them that they might be able to take home and use.
Cook says he agrees, noting that farmers are often the best resource to help other farmers who are struggling with making decisions about adopting a new management practice.
More informational resources and tools are available online from Cook and his team at the Dairyland Initiative.
Links: The Dairyland Initiative Dairyland Initiative Podcast and other resources can be found here.
You can hear the complete discussion between Drs. Cook and Gingrich on “Have You Herd?” at this link: Epi. 221 – Making Cows Comfortable to Improve Lameness and Welfare
