One only has to spend a few minutes with dairyman Lee Jensen to realize that his mind is always moving. He is continually crunching numbers and considering options, looking for the next opportunity to benefit his cows, his fields, and the farm’s bottom line.
This is especially true when it comes to the manure management on Jensen’s dairy operation near Elk Mound, Wis. From anaerobic digestion to a bedding dryer, his commitment to not only removing manure but making it a useful byproduct has led him down several paths that have proven successful on his family’s farm.
Cows at the core
Jensen grew up on a registered Holstein farm in the northwestern part of the state, which was started by his grandfather and later run by his dad and uncle. Jensen began farming full time after graduating from high school and took over the operation with his cousin Jim in 1989.
Jensen’s wife, Jean, is a veterinarian, and she was also managing her family’s dairy farm when they got married in 1996. The three contemplated building another dairy for a few years, and in 2000, they purchased some land and did just that.
The first cows were milked at Five Star Dairy on November 28, 2000. Another freestall barn was added in 2009.
In addition to the 1,100-cow milking herd, the Jensens raise all of their heifers, which are housed on the farm, at the old home farm, and at Jean’s family’s farm. They crop 4,500 acres to grow corn, alfalfa, and soybeans.
The Jensens also run a trucking business. They haul raw milk for 50 dairy farms to ConAgra Foods, and they also transport processed milk product. In addition to milk, they haul whey permeate from the milk plant, distillers grains from an ethanol plant, and sawdust.
Jim manages the trucking business and the crops, while Jean fills the herd manager role and does veterinary work for the farm. Lee is the general manager who oversees feeding and heifer raising.
While the family has diversified its business, “Cows are the heart and soul of what we do,” Jensen said. “We try to provide good feed and do what’s good for the land.”
Open to a digester
The same year he started Five Star Dairy, Jensen toured a farm in Minnesota that had an anaerobic digester, and he liked what he saw. When he returned home, he asked to have a meeting with Dunn Energy Cooperative and Dairyland Power and told them he’d be interested in producing electricity someday. Three years later, working with Microgy Inc. and Dairyland Power Cooperative, an anaerobic digester was installed on his farm in 2005.
At that time, not many dairy farms had digesters and manure solids separators. As the first digester for Dairyland Power, Jensen said he was a bit of a guinea pig. He was also one of the first farms to co-digest different substrates in his digester. Jensen learned a lot about anaerobic digesters over time, and he pointed out different aspects of the digester that he can monitor and control from multiple computers around the farm and his phone.
When it comes to profitability, Jensen said, “Over time, the digester has had high and low points.” He explained that, in general, power companies want renewable energy; solar and wind power are more feasible long term. Technology and mass production are making the electricity they produce more economical for all consumers.
Jensen had a long-term contract with Dairyland Power, so he continued to run the digester and make methane even when the demand wasn’t there. Then, about four years ago, the company offered a buyout and he accepted it.
Serving on the Dunn Energy Cooperative board of directors gave Jensen a deeper perspective on energy production. “Making electricity just isn’t feasible at the current revenues,” he said. “We have good, reliable electricity here in the United States, and they are not going to pay us enough to make the digester profitable.”
He is in the early stages of working with another biogas company to produce CNG (compressed natural gas) vehicle fuel, which he thinks will be a more cost-beneficial outlet for his anaerobic digester in the future.
Turning manure into bedding
Manure solids are separated 24 hours a day, and 50 to 100 pounds of solids bedding are produced per minute. The solids go into the separator in a slurry form. The liquid goes into the manure storage pit and the solids come out at 70% moisture.
While these manure solids were comfortable for the cows, “I couldn’t get somatic cell count as low as I wanted, and there was too much clinical mastitis,” Jensen said. After some thought, he identified what he believed was the missing link.
“My gut feeling was that we needed to put in a dryer,” Jensen explained. He started doing research to see what was on the market.
Jensen decided on a stainless steel, triple pass rotary drum bedding dryer manufactured by McLanahan. It cost a little more, he said, but it is also more efficient. Additionally, it has more safety controls in place, including a fire suppression system, which Jensen appreciated. The system automatically injects water into the dryer if the temperature gets above a predetermined set point, shuts the system down, and alerts Jensen.
Since his was the first biosolids dryer installed on a farm, there was no data he could find to consider, but the dryer came from a reputable company and he had a good feeling about it. He worked with Komro Sales, the local McLanahan dealer, which was the same company that had previously installed their manure pumps and separators. The dryer was installed just over two years ago, and Jensen has been very pleased with the results.
After the manure solids leave the separators, the fibers are moved with conveyor belts into the bedding dryer’s hopper, which is like a TMR mixer. Jensen explained that this ensures even feeding into the dryer. This is not necessary, but the bedding dries more efficiently when the dryer is fed evenly.
Bedding is dry after three to four minutes in the dryer, where it is exposed to temperatures up to 1,000°F, and is discharged at 142°F. The bedding leaving the dryer is about 45% moisture, and tests prove that pathogens are greatly reduced. A conveyor stacks the bedding on a pile once it leaves the dryer, and it is immediately ready for use.
The dryer can run on natural gas, propane, or a combination of the two. It can use methane from the digester as well. Jensen explained that it is less expensive to run in the summer when it is warmer outside and they can use natural gas. In total, electricity costs $4 per hour to run the dryer, separators, and conveyors. The fuel costs range from $6 to $20 per hour.
The dryer is running 10 to 12 hours per day. If not able to visit the separation building physically, Jensen will check the dryer through cameras or an app on his phone every hour to make sure everything is working properly. Overall, though, the dryer operates with little maintenance.
The cows have spoken
Once they installed the bedding dryer, the Jensens converted more of their mattress stalls to deep bedding. They are filled with the dried manure solids four times per week, and the cows seem to prefer them.
“The cows in the deep beds are doing better,” Jensen said. “They lie down more.”
The bedding material doesn’t give the same grip that sand does, so Jensen added more floor grooving in the barns for that reason. In the stalls, though, it is certainly doing its job.
“There’s a cost to running the dryer and it’s another thing to watch, but in my mind, there’s no question that it’s better for the cows,” Jensen said. “It’s softer; the wet bedding packed so hard. It’s dry enough it doesn’t freeze. I’m pretty sold on it.”
The results of improved cow comfort have shown up in the bulk tank. Five Star Dairy started using the dryer at the end of 2017, and the herd’s annual average for energy-corrected milk went from 89.9 pounds to 96 pounds per cow. During the same time frame, their average somatic cell count went from 204,000 to 109,000 cells per milliliter.
Producing high-quality milk while using manure solids as bedding is very important to Jensen. Mastitis hurts reproduction and raises antibiotic use, he said. The dryer is part of the puzzle in maintaining herd health, and he feels their additional milk premiums cover the separation and dryer costs. “The extra 2,000 pounds per cow per year is great, too,” Jensen added.
“I feel good starting up the dryer every day. It makes everyone else’s job on the farm easier,” he said. “The operational costs are significant, but the benefits outweigh that. I wish I would have done it sooner.”
Benefits of composting
The bedded solids have worked very well for the farm, but they still had that affordable supply of sawdust. Jensen decided to build a compost bedded pack barn for far off dry cows, bred heifers, and prefresh and postfresh animals.
“They love it,” Jensen said. “They stay clean. They are comfortable.” The herd health benefits have been positive, too. In four years, he said they have only had one displaced abomasum.
Maintaining a 30,000-pound herd average goes beyond bedding, of course. Cows are grouped by age and size in his three freestall barns, and stalls vary in width to accommodate the different sizes of cows. In this newest barn, the stalls are 50 inches wide with more lunge space.
They utilize rumination and activity monitors to further monitor herd health. Even though reproduction rates are not quite as high as Jensen would like, they have plenty of heifers coming down the pipeline. This means they can be pickier about the heifers they keep.
“We want to make enough heifers, but we want to have the best heifers,” he said. Heifers are bred twice to sexed semen, once to beef semen, and then they are culled if not pregnant.
Changes made to their facilities have also shown up in the milking herd’s cull rate, which is down 10% from what it was just a few years ago. The new compost-bedded pack barn definitely deserves some of the credit for that, along with the drier bedding in the stalls.
Improving the soil
While recycled manure is put to good use in the barn, manure is also seen as a valuable asset for their crop fields. The Jensens haul their own manure, using drag hoses for close fields and trucking to those that are more remote.
Jensen said they have three nutrient management plans to maintain their fields. By using more modern equipment, he feels the soil is in much better shape than it used to be, and crop yields continue to improve.
Some of the separated manure solids are headland stacked on fields that need extra phosphorus. Jensen said it’s particularly good for sandy ground farther away from the dairy. The manure and bedding from the compost-bedded pack barn is also stacked in the fields and used as fertilizer.
Additionally, Jensen has been marketing compost since he started running the digester in 2007. People come out to get compost for their gardens, and it is a chance for them to see the dairy. Money made from selling compost covers the farm’s cost of sawdust, but it’s also an educational opportunity.
“These customers are consumers,” he said, indicating the value of having them personally know a working dairy farm. “There is so much misinformation out there.” The Jensens are eager to educate and open their doors frequently for tours.
Less to store and haul
Yet another benefit of using the dried manure solids as bedding has shown up in the area of manure storage. When they were bedding with sawdust, Jensen said it took two agitators, a pump, and three tractors to clean out their 9 million-gallon manure storage pit. By keeping the solids out, it takes a lot less equipment to empty the pit now as they don’t have to agitate it, and it doesn’t plug up the trucks.
Another feature that reduces the volume in their manure storage is a heavy plastic lagoon cover. Jensen participated in an odor study and got some funding for the cover a decade ago. “It was not cheap, but I am really glad I did it,” Jensen said. The cover has a 20-year guarantee, and after 10 years, it has yet to show wear. “There is no odor, and it enhances storage immensely,” he added.
Just last year alone, Jensen estimates it kept 42 inches of rain out of the lagoon. At a minimum cost of a penny per gallon, that is 1.5 million gallons of liquid that did not have to be pumped out of the lagoon.
Better than average
There is no shortage of diversification and innovation on Five Star Dairy. And behind the technology is Jensen, who keeps a close eye on all aspects of the dairy using computers and his smartphone. He commented on the value that technology brings when combined with good cow sense.
“You still have to go in the barns to look at the cows,” he said, “but milk production and some of the other numbers we can track are things you can’t see in the pens. It goes both ways.”
When the Jensens stopped using BST a few years ago, the herd actually went up in milk production. Jensen credits that to their commitment to do other things better.
“Our goal is to always get better,” Jensen said. “You’re never going to make money if you are average.”
Adding an anaerobic digester set into motion many changes on the farm, with manure management and beyond. Jensen has built an arsenal of knowledge and contacts since then, which continue to improve his dairy.
“The more dots you can connect, the more competitive you can be,” he explained.
This article appeared in the February 2020 issue of Journal of Nutrient Management on pages 10 to 13.
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