There are various ways to house calves on a farm, but not all options are ideal for their health and comfort.
Courtney Halbach and Nigel Cook, hosts of the “Dairyland Initiative Podcast,” explained that building an efficient calf barn facility is essential for a dairy operation, but it’s often more difficult than expected. There are a lot of factors to consider including proper spacing, air quality, ventilation, temperature, bedding type and depth and drainage.
Lack of space (or overstocking) can lead to problems such as increased illness and decreased daily gain. Considering you can’t control exactly when a cow calves, it’s best to overbuild the facility. Halbach and Cook recommend overbuilding by 110% to 125% of your average daily needs, keeping in mind how many animals you plan to keep and how long they’ll stay in that barn.
When it comes to introducing new calves, Halbach explained, “They don’t see a lot of success [with continuous flow systems] because it’s really hard to clean those pens between calves,” so he prefers the all-in, all-out strategy.
When determining the space required per calf, you have to consider both the resting space of the animal and the volume of the barn. Halbach stated, “The average volume of barn per calf is about 1,300 cubic feet.” The minimum resting area for a newborn calf is 35 square feet, but this number can change based on the size of the animal.
Stocking density is the single more determinant of air quality in the calf barn. Air quality measures the amount of airborne bacteria in the pen, and studies have shown that as pen area increases, the number of airborne bacteria and cases of respiratory disease decreases. However, studies have supported that calves separated by solid paneled pens had an increase in airborne bacteria counts but a decrease in respiratory disease. Due to the lack of contact between calves, solid panel pens with openings in the back and front to allow for air movement are a great design option.
Making sure calves have clean bedding and enough space to stay healthy are two priorities in calf barns. Photo by Courtney Llewellyn
Ventilation is needed to displace any moisture, heat and pathogens that are in the barn. There are two main ventilation options to choose from – natural or mechanical ventilation – with fresh air being used either way.
Halbach measures ventilation by air changes per hour (ACH). The minimum recommended ventilation rate for calves is 4 ACH in winter. If the stocking density in the barn is doubled, the ventilation rate can increase to 40 ACH.
When it comes to bedding type, long straw is Halbach’s “gold standard” for calf bedding, but other materials such as sand, wood shavings and cornstalks can be used if the climate does not require nesting ability. Bedding depth is important for calves due to their susceptibility to the cold, as it helps them maintain their thermoneutral zone. This zone is “the range of temperatures that the animal isn’t expending energy to maintain every balance and body temperature,” explained Cook. For a newborn calf, this range would be 50º – 78º F, and 32º – 73º for a month-old calf.
The University of Wisconsin-Madison School of Veterinary Medicine developed a nesting score system to evaluate bedding depth in a barn. If a calf’s legs are completely exposed while laying down, it has a nesting score of 1. If the legs are only partially visible, it’s a nesting score of 2. If the legs are generally not visible and the bedding is dry, that is an ideal nesting score of 3. The closer the score is to 3, the lower the risk of respiratory disease.
Halbach favors concrete floors with a 2% slope, ideally leading the liquid toward the back of the stall. You can have the liquid drain to the middle of the pen, but it’s more likely to get blocked with bedding if you don’t clean the drain regularly.
Considering it can be expensive to provide deep bedding for the calves, some farmers have implemented using gravel as well as the concrete to reduce the bedding amount by as much as 50%. You can use gravel throughout the entire base of the calf pen, in the back half of the pen or even just in the center with concrete sloping toward it.
There are a lot of factors to consider when building a calf barn. “It’s really important that we have an appropriately stocked barn … but also create a dry and comfortable place for our calves to rest,” Halbach said, so they can focus their energy on growing, not maintaining energy balance.
by Kelsi Devolve
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