Managing the mooo-ment
Like most species, the three weeks leading up to and three weeks after giving birth are a time of great change for dairy cows. This time, known as the transition period, often brings about additional inflammation and changes in metabolism that can reduce the cows’ ability to properly intake nutrition and fight off infections and disease, leading to health issues and decreased production at a very crucial time.
“It's a very dramatic period for the cows in terms of their physiology and health because everything's changing so quickly for them,” said Tony Bruinje, assistant professor in dairy production at ĢƵ. “There are a number of cows that unfortunately struggle to adapt biologically to the start of lactation. If not properly managed, one in every four cows can have some sort of health problem during that time.”
The consequences of the health issues brought on by calving can last a lot longer than the transition period itself. The diagnoses are wide-ranging and include having a retained placenta, a uterine disease, mastitis, lameness, difficulty calving or metabolic problems that can oftentimes go unnoticed. Compounding the severity of the situation is that these health problems don’t just appear in first-time mothers, and the cows may not appear sick, making timely diagnosis and treatment difficult.
In the first week of an illness or infection, the cows could see a significant drop in milk production, potentially losing up to five pounds a day for weeks depending on the health problem. Long term, the cow could have fertility issues and would be more likely to have complications surrounding calving in the future.
With the transition period being such an important time for cows and a common time for them to experience some type of health distress, it is imperative that producers have strategies to proactively address cow health.
South Dakota’s dairy industry is one of the fastest-growing dairy states in the country, growing more than 8% annually for the last four years. This reinforces the importance of finding solutions that work for South Dakota producers, which is why researchers at SDSU are working toward finding successful strategies, with two of them taking complimentary but different approaches.
Precision dairy technology
When consumers imagine where their milk comes from, they may picture a farmer on the classic three-legged stool milking their entire herd by hand early in the morning and again in the evening.
In reality, dairy technology has made incredible advancements, resulting in most dairies adding a mechanical system to streamline their process. One option requires a person to connect the cows to a machine for milking two to three times a day. The other option is entirely robotic and milks the cows on their own schedule three-plus times a day. Both systems can be used to track each cow’s individual milk output, and some are able to analyze characteristics of the collected milk.
Many farms are also using wearable monitoring technology in the form of a chipped collar or ear tag, allowing producers to track each individual cow’s activity and feeding behavior among other data that they can then tie back to the same cow’s milk production. By comparing sensor data collected by novel devices, some not currently available on the market, with biological data such as blood samples, Bruinje and his lab members are working to determine if these devices could potentially be used for disease detection. The group works with local commercial dairies and cows at the SDSU Dairy ĢƵ and Training Facility to collect their data.
“We know some cows are having immune system challenges,” said Bruinje, a Department of Dairy and Food Science faculty member. “By comparing the biological markers with the readings on the sensor devices, we can confirm that the sensors are detecting the same changes in these cows.”
Last summer, Bruinje and members of his lab worked with a local dairy to track cows throughout the transition period. They conducted clinical exams of the cows and collected blood samples to evaluate devices that could potentially detect disease in the cows before they become severe. The next step of this project will be to test if the data collected by this device, in combination with wearable sensors the farmer is already using, can predict which cows will have issues, allowing the producer to intervene early and provide treatment if necessary.
“My research is trying to use the existing data streams to identify high-risk cows, or cows that are about to have problems, so that we can intervene before the problems happen,” Bruinje said. “The ultimate goal is to find strategies that producers can use with their own data to monitor cows without having to take samples.”
Improving cow immunity
Identifying which cows in a herd are sick is crucial, but another potential solution is to improve overall cow health at the time of calving.
Turner Swartz, assistant professor in the SDSU Department of Dairy and Food Science, conducts trials of various treatments on small groups of cows with the goal of improving cow health during the transition period to make them less susceptible to common medical issues. One of his studies is determining if a nonsteroidal anti-inflammatory drug, also known as an NSAID, can be used to reduce post-calving inflammation.
“We know that cows around calving experience chronic inflammation, and we think that inflammatory response may be predisposing them to other diseases,” Swartz said. “We’re trying to figure out what we can do for these cows to make them more resilient.”
Another study out of Swartz’s lab is looking at the effects of mycotoxins, a mold that can contaminate grains and grasses in feed. Specifically, the impact their presence can have on cattle immune systems and if they could cause a cow to be more susceptible to disease. Similar to the NSAID study, Swartz is using the experimental method, which allows him to control additional variables that could influence the study outcomes, such as the environment, feed amounts and cow age, and directly compare cows who receive the treatment he is testing with cows who don’t receive the treatment. This strategy gives Swartz and his team the best opportunity to determine if the treatment itself is effective.
“I like to describe our studies as proof of concept. We're doing the groundwork to see if the concept even works,” Swartz said.
Leading the NSAID work for Swartz’s lab is Leticia Camargo da Costa, a second-year master’s student from Colina, Brazil. She is one of several graduate students who are gaining experience by participating in the research trials, conducted at the SDSU Dairy ĢƵ and Training Facility in Brookings. Camargo da Costa manages data collection, including milk and blood samples, that she then analyzes to assess milk quality and immune function. She will present results from the NSAID trial to the American Dairy Science Association later this summer.
Part of Camargo da Costa’s role involves overseeing undergraduate students who are hired to help take care of the research cows’ daily needs such as mixing feed, milking and observing animal health. Cows are brought to the facility specifically for research projects and to provide hands-on experiences for students, something Camargo da Costa believes has prepared her well for the post-graduation job market.
“I have been learning a lot. Every day I feel a little bit more prepared to be out there (in the industry),” she said. “I believe SDSU gave me great support, I feel like the research gave me a really good background and I got a really good experience here.”
