TAKE HOME MESSAGES

• Dollar savings can be achieved by incorporating a number of energy saving technologies in the dairy operation.
• Proper ventilation is critical for animal heath and production.
• "Cold housing" is the recommended system for raising dairy herd replacements.

Dairy producers are often thinking of and planning new construction or remodeling possibilities for the dairy facility. As current facilities wear out or expansion is needed, producers have the opportunity to improve the old with newer technologies. Attention is usually focused on the design factors relating to the needs of nutrition, animal health, production performance and labor requirements. This is logical since these factors account for 75 to 80 percent of the costs to produce milk. However, energy costs, although a smaller expense, also deserve close attention as the dairy producer attempts to produce milk at the lowest price possible. When preparing to build or remodel the dairy facilities, producers need to realize that placing priority on energy conservation can increase the energy efficiency of the dairy operation and improve the profit margin.

ENERGY USAGE

Energy audits conducted on dairy farms show considerable variation in energy use. A typical breakdown of electrical and liquid fuel energy use in dairy farming would consist of:

• livestock waste removal - 26%
• livestock related farm travel, miscellaneous - 21%
• water heating - 16%
• milk cooling - 12%
• milking - 10%
• feed processing and distribution - 8%
• ventilation, supplemental heating and lighting - 7%

Efficient energy use and conservation should be incorporated in the milking center environment. Larger herds will use a greater percentage of energy cooling milk and a lower percentage for heating water. The reverse is true on smaller farms. Some kind of heat transfer and/or heat recovery units are becoming standard equipment on dairy farms. Energy savings are sufficient to show a 3 to 4 year payback period. The heat given off from air-cooled compressors is directed inside the milk room for supplemental winter heat. Air-cooled condensers must be kept clean and its airflow unrestricted. Poor airflow can raise the operating temperature of the condenser which requires 10 to 20 percent more electrical energy. Installing a heat exchanger in combination with bulk tank cooling reduces milk cooling costs by 20 to 60 percent. To gain the most benefit of a pre-cooler for energy savings, plan to use the warmed water for cattle waters or reducing the water heating energy needs.

Efforts to reduce energy costs related to feed processing and distribution is of a lessor concern than other farm operations. Deciding which feeding system to use on the dairy farm will depend more on the goals of the feeding program than the energy conserved. These goals include flexibility in feeding and reducing time and labor. Generally, the more mechanized equipment will cost more initially and require greater repair and energy costs. However, mechanization does reduce physical labor and can deliver a proper diet to the dairy cow if the feedstuffs are weighed and monitored properly. A proper diet does not mean the cows are eating a balanced diet. Because cows have individual preferences for different feedstuffs a cow may or may not consume a balanced diet. Total mixed ration (TMR) will provide the best assurance that the animals are eating a balanced diet.

HOUSING CONSIDERATIONS

Ventilation is vital to any livestock building environment. It is the key to allowing cattle access to clean, fresh air and a dry housing environment. Recognizing that proper housing ventilation can be accomplished with mechanical systems, one has to consider the initial cost and the expected energy costs from fan usage and needed supplemental heat. Natural ventilated "cold barns" can provide excellent cattle housing conditions as long as they remain dry and draft free. Natural ventilated freestall barns need to be designed properly to encourage optimum air flow into and out of the building through planned openings. The following guidelines are suggested:

• continuous open ridge that provides 2 inches of open space per every 10 feet of building width.
• large sidewall openings for summer use and partial sidewall opening for winter use.
• continuous eave openings on both sides of the building equal to 2 of the ridge opening.
• provide sidewall height of 12 to 14 feet high. Minimum of 10 feet.
• construct the roof slope at a minimum of 4/12 and a maximum of 6/12 pitch.

Ridge caps are not recommended. When fully occupied, only minimal rain or snow will enter the building. If ridge caps are used they must be designed properly or they may actually increase the amount of precipitation entering the building (Figure 1).

During the summer months fans will be needed to provide cooling for the cattle. Fans can present a substantial increase in electrical energy usage, especially when open-blade or box fans are used generously throughout the barn. Proper fan size and spacing in combination with a sprinkler (soaker) system will provide a powerful cooling effect while reducing the fan power needed. The 36 inch horizontal-axis fan should be spaced every 30 feet and a 48 inch fan every 40 feet. The sprinkler system will operate most efficiently when regulated by a timer and thermostat. A cycle of 1 minute on and 10 minutes off usually does an adequate job of wetting the cows while conserving water and energy. The use of natural ventilation, fans, and sprinkler system is extremely cost effective when monitoring the improved milk production and reproduction ability of the heat stressed cow.

A recent innovation in housing for dairy calves and cows has been the greenhouse barns. The thought of the bright atmosphere and warmer solar heat on winter days have brought attention to the hoop or quonset type structure. Since these structures are relatively new to the dairy industry there is still some discussion over which barn, the greenhouse or post frame barn, is the most cost effective. Greenhouses, like other "cold barns", must be properly ventilated. Natural ventilation with a greenhouse barn requires more careful management than with the conventional barns. In the summer, greenhouse barns must be covered with shade cloth to provide protection from the solar energy. A cost comparative study conducted in Wisconsin suggests no difference between the total cost of a greenhouse and a post frame construction.

REPLACEMENT HEIFER HOUSING

Natural ventilated "cold housing" is the recommended system over "warm housing" for raising young dairy calves. Several advantages include; cheaper to construct, requires less energy costs, calves are healthier due to less animal disease build-up and requires less labor to manage. It is suggested to use calf hutches from birth to weaning, followed by transition housing and then to a larger group pen with loose housing or freestalls. Even though older heifers can withstand more stress, they still must be provided shelter and dry conditions. There are a number of housing options for heifers 4 months to calving. These include counter-sloped barn, gated bedded pack and freestalls. In open front housing, provide enough pen depth to shelter the animals from winter winds and locate the open front to the south or east to take advantage of the natural solar energy.

Funds for this presentation were provided by a 1998 Illinois Department of Commerce and Community Affairs grant.