Dan McFarland, Penn State Extension ag engineer, said empty dairy barns provide an opportunity for those who want to remain involved in livestock production. The process of converting an existing dairy barn for beef cattle production should begin with a careful evaluation of the facility, animal needs and producer needs.
“There are a lot of similarities from dairy to beef,” said McFarland. “When I design any kind of system, I’m an advocate for the animal – that’s the most important to me. We want to make sure calves perform properly, completely, consistently and safely. Animal handling and care should be with as little excitement to both animal and caregiver as possible.”
McFarland listed adequate ventilation to control moisture and gases, adequate space, suitable resting area, good access to feed and water and confident footing to avoid slipping as key components to consider when reconfiguring buildings. Caregiver needs such as feed delivery, bedding and manure removal should be convenient and easy.
Every existing building is unique – there’s no single model for evaluating a structure. “Most people overestimate the value of an existing building and underestimate the cost of renovating it for an alternative use,” said McFarland. “A new building, without electricity or water, will cost $18 to $22 per square foot.”
Conducting an evaluation of an old building involves assessing the condition of the roof, structural beams, walls, utilities, drainage around the site and condition of concrete. The potential for long-term issues and costs are related to anything that will cause animal discomfort or stress. Inadequate ventilation, building layout and anything that leads to worker frustration influence long-term costs.
Another consideration is the amount of material that must be removed prior to renovation. McFarland said the cost for removing an old concrete floor may cost as much as having a new floor installed. The renovation of a key component such as a roof may cost more than for a new building.
As a rule of thumb, McFarland said if a remodel costs two-thirds to three-quarters the cost of a new building, the new building will be a better choice. “It will be better ventilated and will allow better traffic patterns for cattle and equipment,” he said.
As is the case with real estate, location is everything. “No amount of money, creativity, engineering experience or additional equipment can make up for a building in the wrong place for its intended use,” he said. “Are the roads near the facility suitable for equipment such as cattle trucks and feed handling?”
The water source needs to be sufficient to meet animal needs year-round and should be frost-proof. In general, beeves require 10 to 20 gallons daily per animal. Electricity should be adequate for fans and lighting, including exterior safety lighting. Consider internet availability if the production system will include electronic data.
Surface and subsurface drainage can influence odors and water quality. The building and surrounding land should be compliant with local codes and ordinances. If necessary, would a
32Consider whether interior space is sufficient for the intended animal population, and whether support posts and walls are sound. In general, beef cattle require 30 to 35 square feet per head. (For comparison, a queen-size mattress is 35 square feet.)
Many old bank barns have posts that may hinder cleaning, bedding and moving animals. Old barns often have low ceilings that may make it impossible to use large, modern equipment to enter the space for cleaning. In some cases, support posts can be relocated, but it’s important to determine the safety and cost of such a move.
McFarland focuses on air quality and ventilation as critical components for animal and caretaker health. “Cows are homeothermic,” he said. “If they’re fed properly, they can maintain a constant body temperature over a wide range of temperatures. Most cattle are overtaxed more by heat than by cold.” He added that if cattle are protected from direct wind exposure and have a dry coat that isn’t matted, they can maintain sufficient body heat in cold weather.
The thermo-comfort zone is the temperature range in which an animal can maintain heat production and continue good dry matter intake for optimum production. For cattle, the zone is between 41º and 68º F.
Moisture production by animals directly affects animal health. “At 30º, each animal produces about one pint of water per hour,” said McFarland. “Forty steers will add about five gallons each hour to their environment. That needs to be removed for animal health and building health.”
Proper air exchange involves controlling moisture levels, managing gases such as ammonia and methane and controlling pollutants from bedding material, dust and dander. “We also want to provide uniform distribution,” said McFarland. “We want a good blend of quality air throughout the entire animal space.”
Ventilation involves two holes: one to let fresh air in and one to let stale air out. As inlet air enters the building, it mixes with moisture, gases, dust and pollutants. “Air is a gas, so it expands and contracts with temperature,” he said. “In colder temperatures, there’s a smaller sphere of air with a large amount of moisture – maybe 80% moisture on some days. In warmer temperatures, air comes into the barn with the same moisture, but now the air is expanding and makes it available to pick up more moisture. A 20º difference in temperature doubles the moisture-holding capacity of a volume of air.”
Natural ventilation uses wind speed and direction to create pressure differences between the inside and outside of the building. “Pressure wants to move from high to low,” said McFarland. “Natural ventilation needs to provide protection from cold winds and precipitation – keep animals dry and out of the wind to reduce wind chill.”
In summer, the ideal building functions as a shade pavilion. When there’s an outside breeze, air exchange usually remains good. However, when wind isn’t blowing, air exchange is less than ideal, so building orientation is critical. Air exchange is also driven by animal heat – warm air rises. Wind speed as low as 1 mph can handle air exchange driven by heat.
Mechanical ventilation uses exhaust fans to lower the pressure inside a building. However, costs to consider include fans, installation, operation and maintenance.
“Circulation fans do not create air exchange,” said McFarland. “But they do blend air, minimize stratification throughout the building and provide more uniform air quality. In hot weather, they can help animals more efficiently get rid of heat.” He cautioned that improperly spaced fans that lack uniform air speed can result in animal bunching.
Farmers may be able to use existing buildings to raise a different kind of livestock, but it’s important to spend time examining every aspect of a project to make the right decision for both the animals and the humans involved.
by Sally Colby