Source: Cornell University, By Alexandra Chang
With the sweet and tangy scent of silage in the air, dairy cows wait expectantly for a pat on the head while a tractor rumbles in the distance. The first moments in a dairy barn may seem like a step into the agrarian past, but take another look. New York’s milky way includes bovine Fitbits, genetic screenings of milk, and farmers with pilot licenses for their crop-monitoring drones.
It could be argued that New York’s dairy industry is already at the top of its game. Ranked third nationally in milk production, the Empire State is first in the production of yogurt, cream cheese, sour cream and cottage cheese. Milk production is measured in the billions of pounds; revenue, in the billions of dollars. But change is afoot. While quantity still counts, the driving aspiration is quality—quality of life for the cows, quality of milk as an ingredient, and the quality of the environment and downstream ecosystems—expedited by emerging technologies and CALS expertise.
Research on quality of life for dairy cows centers on the concept of cow comfort, which now drives barn design innovations including the use of sand for bedding and enhanced cooling systems. But if cows could speak, veterinarians would likely get an earful about hooves. Periods of hoof discomfort and lameness strike many dairy cows at some point in their lives. Udders, too, would likely be a common complaint. Capable of producing more than ten gallons of milk a day, they are sensitive organs at risk for inflammation and infection.
Heather Huson ′97, professor of animal science, thinks untapped potential to improve cow comfort lies in the genome. Her approach—what she calls the “the nerd side” of the dairy industry—is to pursue the genetic signatures of hoof and udder health. Converted into genetic screens, they can give breeders the power to select healthier, more contented cattle. Evaluating cows for breeding is nothing new—the first written records of cattle breeding date to a Swiss monastery in 1775—and at cattle auction today the sales pitch may include information on a cow’s genetic predisposition for traits from milk fat and conception rate to foot angle. Huson’s research is laying the groundwork for new genetic screens for hoof and udder health.
Graduate student Cassandra Stambuk is Huson’s chief bovine podiatrist. She’s taken hundreds of ultrasound measurements of cow hooves, also monitoring and scoring their gait. The ultrasound gives her a detailed look at the cow’s digital cushion, the soft padding inside of hooves. A thicker cushion offers more protection from lameness.
Huson’s team measures udder health just as thoroughly, identifying all the bacteria present in milk using DNA sequencing. The hoof and udder data from the cows, paired with the cow’s own DNA samples, will allow them to scan the genome for regions associated with udder inflammation and hoof cushioning. Tagging these sites with new genetic markers will create a tool for breeding for quality of life in about three to five years, Huson said.
“Genetics is not a one-year turnaround, it’s not a nutritional supplement where you can see the animal change or grow right away,” she said. “But the dairy industry is eager to use our research—they are organized and proactive.”
Next on the list of challenges to cow comfort: heat and humidity. Cows are most comfortable, and most productive, at temperatures below 70 degrees. Heat stress increases and milk production decreases as the temperature climbs, and climate change has increased the number of days New York cows currently experience heat stress to an average of 64 days per year. For now, a farmer’s best option is upgrading ventilation, misting and spraying the herd with water, and providing cool, sandy bedding. A cow’s best option is to pant and sweat.
Kifle Gebremedhin, professor of biological and environmental engineering, thinks that cows can be bred to be better at sweating. His research group designed a portable sweat meter to track temperature and relative humidity in cattle. What they saw was intriguing: the animals sweat in a cyclic fashion rather than constantly; different breeds have different sweating rates; coat color has an indirect effect; and some sweat glands are present but non-functional.
“Knowing the genetics behind this process, we can try to enhance the frequency of the sweat glands to help the animals sweat more,” Gebremedhin said. “There are also sweat glands that don’t sweat. Can we entice them and make these redundant glands sweat?”
Researchers have strong allies in the dairy industry for their work on cow comfort, where affection for the herd is a strong motivator for management. Julio Giordano, assistant professor of animal science, sees it firsthand on his many projects with dairy farm collaborators.
“We have an opportunity to identify diseases earlier, to improve response to treatment. It gives farmers peace of mind and allows them to spend less time doing things that a machine can do. Technology is awesome. Automation in general will play a major role in the future of dairy farming.”
“Dairy farmers love their cows,” he said. “To farmers, the happier their cows are, the better.”
Originally from a dairy region in Argentina, Giordano said he too fell in love with cows at a young age. Today, he is doing his part for cow happiness with an assist from technology: using sensors to swiftly identify cows in the early stages of illness so they can be treated promptly.
In a recent study involving more than 1,000 cows at a commercial farm, Fitbit-like sensors on their collars and ears tracked activity level and rumination time. One of the best indicators of a healthy cow is her appetite, so digestion was monitored using an audio sensor that listens in for the steady rumble of a cow chewing her cud. The continuous tracking allowed for changes in activity and rumination to be noted; a cow who moved less or stopped eating triggered the system’s alarm.
The approach was very successful in identifying cows with metabolic and digestive disorders; 90 percent of sick animals were diagnosed by sensor. For other common health issues, such as inflammation of the udders, the system needs more fine-tuning. Going forward, Giordano wants to combine additional sensors to improve disease prediction and prevention.
“We have an opportunity to identify diseases earlier, to improve response to treatment,” Giordano said. “It gives farmers peace of mind and allows them to spend less time doing things that a machine can do. Technology is awesome. Automation in general will play a major role in the future of dairy farming.”
A technology that has become integral to cow nutrition—conservatively estimated to be used in feeding over 40 percent of cows in the United States—is software first developed by CALS scientists in the late 1980s. The Cornell Net Carbohydrate and Protein System has been in continuous development, and it has been advanced over the past two decades to the point where it can predict the specific amount of amino acids required by an individual cow.
“That’s revolutionary in a lactating cow, because all of a sudden we’re removing ambiguous terms in diet formulation and feed descriptions,” said professor of animal science Michael Van Amburgh, Ph.D. ′96. This allows the researcher and the farmer to become very precise in feeding cows, who spend most of their waking hours in a state of digestion—an estimated five hours a day of eating and another seven to ten ruminating.
“In part because of better nutrition, we’ve gained better herd health, and we continue to grow in milk production per cow in New York state,” said Tom Overton ′91, professor of animal science and director of PRO-DAIRY, a dairy research and education extension program run jointly by the New York State Department of Agriculture and Markets and CALS. “And one thing that Cornell has always done well is to translate the research through extension and outreach, such that it comes to life in the real world.”
However, a more nutritious diet doesn’t just benefit a cow’s health or milk yield. Removing unnecessary amino acids also keeps excess nitrogen out of the environment, improving air and water quality as well as decreasing greenhouse gas production on dairy farms.
“To reduce the environmental impact of the cow is tremendous,” Van Amburgh said. “We can’t send it to zero because all metabolism isn’t perfect, but we can reduce it by 30 to 50 percent. When it comes to the environmental impacts of dairy farming, that’s really significant.”
Shrinking the environmental hoof print of dairies doesn’t start with what goes into the feed trough, though. Professor of nutrient management Quirine Ketterings has her eye on the acres that produce the feed. In the fall of 2000, Ketterings launched the Nutrient Management Spear Program to provide guidance for managing nutrients on fields of silage and forage. A primary goal is developing strategies to reduce runoff and leaching of nutrients like nitrogen and phosphorus from dairy farms into the environment and surrounding watersheds. All this while still running a productive, profitable farm.
“The goal is to grow crops year-round for the environmental benefits, like improving the soil and adding or retaining nitrogen,” Ketterings said. “We work with different rotations to try to improve productivity per field, per acre. When you have higher yields, you have to import less onto the farm, and it helps with the whole farm balance, an important environmental indicator for us.”
This summer Ketterings pursued several projects, such as testing manure as a replacement for nitrogen fertilizer in corn at planting time, development of the next phase of a phosphorus risk assessment tool for the Northeast, and coming up with guidelines for on-farm use of acid whey, a by-product of making Greek-style yogurt. Like Giordano, Ketterings sees a future where new technologies can help on the farm, including tractor-mounted crop sensors and unmanned aerial vehicles, more commonly known as drones, to predict yield and real-time fertilizer needs.
The quadcopter—a commercially available agricultural drone that requires a licensed pilot at the controls—is increasingly being used for precision crop management. In currently ongoing work, Ketterings and colleagues are assessing a crop’s nitrogen status by measuring the wavelengths of light reflected by the leaves and the soil, snapping photos up to 300 feet above the field with three different cameras.
“Embracing technology, knowing your yields, using crop sensors and drones—anything that can allow us to collect large amounts of data, more quickly conduct on-farm research, and then immediately transfer to more efficient farming practices—are the future of crop management,” Kettering predicts.
And what about the dairy products themselves? Martin Wiedmann, Ph.D. ′97, the Gellert Family Professor in Food Safety, thinks we can improve the quality of milk as an ingredient. Fresh raw milk is far from a uniform product. The bacteria it carries can vary from batch to batch and farm to farm. Breed, feed and environment can affect the relative proportions of fat, carbohydrate, protein and vitamins, and make a milk better suited to making cheese or powdered milk, for example.
“What measurements do you need to take in the milk? That’s where we come in,” Wiedmann said.
Wiedmann and the team at the Food Safety Laboratory and Milk Quality Improvement Program create tools to categorize raw milks for efficient production of specific dairy products. The goal: reduce waste, improve product quality and make a more sustainable dairy system. They are developing DNA fingerprinting tools that can identify bacteria in raw milk so that “not only can we name it, we can call up the genetic fingerprint and warn if it’s going to cause issues during cheese making,” Wiedmann said.
The fingerprinting tools can also help them zero in on the source of bacterial contamination—whether it’s on the farm in the bedding or feed, or at the processing plant. Already, Wiedmann’s lab has identified a group of organisms that lower the quality of powdered milk and traced it back to its source on the farm. They continue to develop new fingerprinting tools to identify more bacteria in pursuit of the long-term objective of allowing farmers and processors to adjust and optimize their operations for the dairy product of interest.
“What’s unique about dairy cattle? They can take grasses and forages that do not provide high-quality nutrients for humans and convert it into a food, milk, that has extremely high-quality nutrients for humans.”
“What I see as the big opportunity for the dairy industry is to take a systems approach,” Wiedmann said, adding that, right now, farmers are optimizing production without necessarily knowing all the attributes that increase the value of raw milk for the processor. “The idea is to integrate that system to make it overall more efficient, and ultimately make it more competitive with other food products,” he added.
When asked why they spend their time working toward improving dairy, CALS researchers voice their belief in the product and its future. In part, it’s because cows are a critical connection in our food system that hasn’t budged, even with a century of changing dairy practices and consumer tastes.
“What’s unique about dairy cattle? They can take grasses and forages that do not provide high-quality nutrients for humans and convert it into a food, milk, that has extremely high-quality nutrients for humans,” Wiedmann said. “I have a strong conviction that dairy plays a very important role in global food security.”