Dairy Initiatives

Dairy

Department of Animal Science

D A I R Y   I n i t i a t i v e s   N E W S L E T T E R
V o l u m e   1 0      I s s u e   3       F a l l   2 0 0 1

From the Frying Pan
Into the Icebox

KEVIN JANNI
Department of Biosystems and Agricultural Engineering, University of Minnesota

The heat and humidity this past summer produced heat stress for lactating and pregnant cows. The high daily maximums and some dew-point temperatures as high as 80 degrees F produced temperature humidity indexes over 85, which is considered stressful. Record warm overnight minimum temperatures added to the heat stress because cows could not get relief at night. Many producers used sprinklers and fans to help cows deal with the heat. University of Minnesota professor and Extension climatologist Mark Seeley reported that the combination of heat (temperatures in the 90s) and humidity (dew-point temperatures of 75 degrees F or higher) has roughly a 1 percent probability based on Minnesota's historical climate records.

While the memory of this summer's heat and humidity is still fresh, it's hard to begin preparing for the cold weather and precipitation expected this winter. Historical data indicate that much of Minnesota can expect to have 35 hours of air temperatures of Ð20 degrees F or lower. And much of the state has record lows around Ð40 degrees F.

Cold weather preparations need to address all aspects of the dairy operation to keep it running smoothly. Consider the effects of cold temperatures, wind, snow, and ice on all operations and activities -- including feed preparation and delivery, manure handling, barn and milking center ventilation, and the movement of people, equipment, and milk trucks. Be prepared for difficult situations such as power outages, blizzards, extended periods of cold weather, impassable roads, frozen water pipes, and equipment failures. Train people to use backup equipment and tools. Discuss priorities, emergency procedures, and expectations with all employees. Identify decision makers.

Dairy animals can do very well in cold weather if they have a clean and dry resting area with plenty of draft-free fresh air. Damp, drafty spaces can chill the animals. Moist conditions can allow airborne pathogens to survive longer, increasing the chances for a disease outbreak.

Animals also need adequate fresh, good-quality feed and water. When preparing for cold weather, think about how you can provide proper environmental conditions with the available facilities.

To prepare for cold weather:

Mechanically ventilated barns and milking centers

Make sure that shutters on fans open and close freely. Clean and apply graphite (not oil or grease) to fan shutter hinges.

Check and clean fans. Follow manufacturer guidelines.

Check gable and soffit air inlets for blockages and plugged screens. Clean and restore airflow.

Check and clean heaters for increased efficiency and safe operation. Follow manufacturer recommendations.

Clean thermostats. Check settings and operation.

Repair broken windows and doors. Reduce leaks to minimize drafts. Lubricate for easier operation.

Cover hot-weather ventilating fans with plastic to reduce infiltration and drafts.

Review cold weather ventilation plans to provide adequate air exchange to avoid damp conditions and excessive condensation on building surfaces.

Naturally ventilated barns

Check curtains and lubricate doors so that they can be easily opened and closed.

Repair ripped curtains and damaged doors to reduce drafts.

Check eave inlets for blockages and plugged screens.

Set management guidelines to provide adequate air exchange during cold weather. Avoid damp conditions and excessive condensation on building surfaces.

Equipment checks

Check and test standby generators. Follow manufacturer recommendations.

Weatherize all engines and equipment. Follow manufacturer recommendations.

Review cold weather starting and operating procedures for all equipment.

Prepare snow removal equipment.

Check water lines to minimize frozen pipes. Drain sprinkler system.

D A I R Y    I n i t i a t i v e s    N E W S L E T T E R
Volume 10    Issue 3    Fall 2001