It’s all about making a good thing even better. Individual hutches, commonly called the “gold standard” for nursing calves, can be made into optimal environments with site considerations and management techniques.
In the same way, individual or group nursery calf barns can be healthy environments if designed and managed well, Dr. Rebecca Brotzman, Outreach Specialist for The Dairyland Initiative at the University of Wisconsin School of Veterinary Medicine, told listeners during the second in a three-part World Class Webinar series being presented by Professional Dairy Producers of Wisconsin.
The first issue is sizing. Plan for 25-30% more space than used at the farm’s average calving rate. That will allow a week or two for pen cleanup and calving surges. “This is not a surplus,” Brotzman pointed out.
Hints for Hutches
Because separation, in both space and time, helps prevent the spread of disease, hutches remain the “gold standard” for nursing calf housing. They are also the best way to provide individual attention and care, and allow caretakers to monitor feed and water consumption.
Hutches are also easily ventilated, with good air quality. The calf has more control, Brotzman pointed out, since she can go in and out of the hutch for fresh air, warmth and cold.
The base is important and should be prepared well in order for liquids to drain away. Remove the topsoil, then add a good layer of rock, top it with small gravel or sand and pack it down.
Some dairy producers pour concrete driveways, while others pour a driving surface around the gravel pads. These can be designed so a skid steer can drive over the pads, facilitating chores and cleanup.
It’s also a nice idea to have the entire area fenced in for security and safety, Brotzman added.
Hutches should be organized well for ease of access and disease control. The calves can be ordered by age in a layout that offers access for feeding and care, and allows for exposure of previously used plots for sanitation.
“When cleaning hutches, sunshine is great, but unless all dirt, straw and manure are removed, pathogens are still there,” Brotzman warned. “Organic matter renders chemical cleaners ineffective”.
It’s a good idea to allow the plot itself to dry. Allow enough space between hutches so each can be shifted over or back and forth, allowing exposure to the weather. “This also allows workers to move between rows,” Brotzman noted.
If space is limited, one option is to switch the orientation and stagger the hutches, allowing five hutches in the place of four. “It means more walking, but if space is limited, this might be a workable option,” she said.
A good hutch is at least 4x8 feet with feed and liquid buckets outside in an outdoor run around 4x5 feet. There should be a divider between the buckets.
For heat abatement, cinder blocks can be used to prop the back of the hutch up. Studies show they work, Brotzman noted, providing decreased respiration rates in calves and improved air quality (carbon dioxide) levels.
Shade/solar radiation protection such as opaque materials and reflective insulation covers can reduce the heat load, but be careful to avoid blocking wind and natural ventilation with low roof structures. “Keep the roof high enough to avoid dead air and pneumonia problems,” she advised.
Sand bedding supports less fly larvae growth, but it is less insulating than straw so calf growers need to keep an eye on temperatures in early and late summer. “Remember, the lower critical temperature of most calves is around 50 degrees,” Brotzman said, noting May and September can have average overnight lows of 49 degrees. “Some nights, a calf will be using energy to keep herself warm, rather than grow.”
Calf jackets are a good idea, either with sand or when fluffy bedding gets packed down, she said.
Digging out the calves after a big snowstorm is a lot of work and must be done before the calves can be feed or bedded. One option is to move the hutch’s outdoor panel up against the front of the hutch before the storm hits. Afterwards, a skid steer can quickly and easily clear away the snow and the panel can be pulled back into place.
The problem with calf hutches are with the workers. “It’s a tough job in the rain and wind and snow, and if workers are miserable, they are not going to take as good of care of the calves as they could,” Brotzman pointed out.
Big Ideas for Calf Barns
The key features of a preferred calf barn is space and deep bedding. Figure a spacial allowance of 30 square feet or more of bedded space per calf, not including the service alleys... The barn should have deeply bedded surfaces in cool weather, considered anything less than 50 degrees.
Larger pens mean lower concentrations of pathogens, Brotzman explained. The calves will spread themselves out and, at 35 square feet per calf, will not be sharing air zones.
Since the thermoneutral zone is 50- to 78-degrees for a newborn calf and 32- to 73-degrees for a month-old calf, make sure calves are deeply bedded. That means “World Expo style”, Brotzman said, meaning the legs are not visible when the calf is lying down.
Studies show that just adding more bedding will decrease the prevalence of respiratory disease. “We really stress this point because it has such a great effect on the calf,” she said. “She can stay warm and separated from the muck and mire that builds up below.”
Another key feature is drainage below the bedding. In trials, all bedding cores averaged 50% moisture. “That’s a really wet bed,” Brotzman said.
It’s also important that caregivers avoid stepping into the pen drainage and tracking it around the barn. Doing so can create problems with pathogen transmission and added moisture to the barn air.
Drainage can be improved with drain tiles installed under the bedding. One good option is creating a base of about 1.5-foot of gravel with a 4-inch drain tile to carry liquids to outside storage. The gravel/tile base will eventually plug, requiring replacement every 1-3 years.
Farms using this method report about 60% of the straw is needed to achieve an equivalent depth and improved dryness, compared to a full concrete base, Brotzman noted.
Barn bases can also be of limestone screenings, with sand used for summer bedding and straw for winter.
If the barn base is concrete, it should be sloped to a gutter in the rear of the pen. If single calf pens are used, the gutter should be in front to keep the pail water out of the bedding.
Natural ventilation with positive pressure supplemental ventilation is now the standard for calf barns. “It helps us use the benefits of wind”, Brotzman noted.
For heat abatement, air movement is important, but studies show proper ventilation positively affects calf health. “Don’t just recirculate air. The calves need fresh air,” she underlined.
Preferred Features of Barns with Individual Pens
Narrow barns with widths of 35-feet or less featuring one or two rows of pens are now preferred. They are easier to ventilate and to avoid placing oldest calves across the aisle from the youngest calves, which reduces the risk of transmitting disease.
Barns should have an east/west orientation to avoid extreme afternoon sun that the calf can’t escape.
Large dairies are constructing multiple smaller all-in/all-out barns that allow more narrow-width age groups, Brotzman said. She recommends such facilities, which allow for complete cleanout and a week to dry between groups.
Calf pens should be separated from a barn’s outer wall by a 3-foot space that can be used as a service alley. The separation allows the cold air to drop from the curtains into the alley. If it is not possible to shift the pens in, the pens can be covered to protect the calves from the cold air drop and a tube system with appropriate air change capacity installed.
Solid panels between the calf pens are a key factor for improving respiratory health, but they are a confounding issue since they reduce air circulation. The ideal pen has fewer solid sides, Brotzman said, advising open front and rear panels with solid dividers extending beyond the ends to keep the calves separate.
She suggested visiting The Dairyland Initiative website (dairlyandinitiative.vetmed.
The series continues on with “Animal Well-Being Concerns For Every Calf Caretaker”. Brotzman will discuss husbandry issues that need to be addressed on every dairy to ensure societal license and healthier, more productive future additions to the milking herd.