Winter can be a rough time for the milking herd. There can be freezing rain, snow, wind chill, very cold temperatures, warm ups, then cold temperatures again. All of these conditions can take a toll on the dairy cow and milk production.
However, dairy cows will do quite well in cold temperatures if they are dry, protected from wind, and properly fed and watered. According to Neil Broadwater, Regional Extension Educator for Livestock, here are some reminders for dairy producers in taking care of their milking herd during very cold weather:
- Water. Dairy cows need water, or they won't eat, which will affect the cow's health and milk production. Be sure waterers or water tanks are not frozen. Cows can draw water at a rate of 3 to 5 gallons per minute, so the water supply and system needs to keep up with demand. Don't allow the water to get too hot or cold. The best temperature for drinkable water is between 40 degrees and 65 degrees F.
Use a thermometer to check waterers with heaters to detect whether or not a heating element is working properly. Even a small limitation in water intake will decrease dry matter intake by 1-2 pounds daily which could limit peak milk production by 2-5 pounds. Lactating dairy cows require 4.5-5 pounds of water (includes both drinking water and moisture in the consumed ration) per pound of milk produced.
- Feed. A dairy cow's need for nutrients goes up as the temperature drops and winter winds increase. Watch body condition. Cows in less than moderate condition will find it much harder to stay warm. Their energy requirements will be higher. Under diverse environmental conditions, it is critical that dietary energy be adjusted. Producers should ask their feed consultant to calculate a "standby" ration for the dairy herd that can be mixed and fed during those extremely cold weather days. Keep on hand in a convenient location for easy reference for those days when this ration is needed.
- Managing Wind Chill. Wind speeds of 5 mph or less or temperatures as low as -20 degrees F can be tolerated. On the other hand, with extremely high winds (35 mph) and temperatures as high as 15 degrees F, wind chill could be a problem.
Therefore, any time cows exit a parlor into wind chill conditions of -25 degrees F or lower, preventive steps need to be taken to prevent frostbite even when the teat is dry. Protection from winds around parlor exits and feed bunks located outside buildings should be provided.
- Free-Stall Ventilation. Do not close eave inlets during cold weather. This will restrict the ventilating rate and create wet, damp conditions and lead to respiratory health problems in the cows. Wet, damp conditions will be evidenced by fog, condensation or frost on building surfaces, and high humidity. During severe cold weather and blizzard conditions, eave inlets can be partially closed to reduce airflow and the amount of snow blowing into the barn. The guideline is to have a minimum inlet opening during severe cold weather of one-half inch for each 10 ft of building width. When normal winter weather returns, eave inlets should be reopened to the standard one inch per 10 feet on both sides of the building.
- Stall Barn Ventilation. Proper maintenance of barn wall fans is important for good ventilation. Keep all fans, shutters, and other equipment clean and properly lubricated. Adjust and replace belts as required. Even during the coldest of temperatures, for stall barn ventilation to work properly, fresh air inlets must still allow air into the barn to replace "old" air being removed. Extension Ag. Engineers recommend four air exchanges per hour for enclosed environments during the winter.
- Prevent Drafts. Cows need a dry, draft-free resting area. Check for drafts near doors, windows, and haymow openings if housing the herd in a stall barn. In free-stall barns, drafty conditions at cow level can be reduced by patching curtain holes, minimizing gaps at the ends of curtains, and sealing around doors to eliminate small gaps where the wind blows through.
- Teat Dip during cold weather? Research shows that consistent use of an effective teat dip is a very important mastitis control procedure. Having dry teats when the cow leaves the parlor is extremely important during cold weather. Omitting teat dipping does not assure that teats are dry.
Dairy scientists suggest that in severe cold, even the thin milk film should be dried before the cow is turned out of the parlor. Instead of not teat dipping, teat dip using a 30-second contact time and then wipe teats dry. This procedure does add a few additional seconds per cow during each milking. However, the benefits of teat dipping in the reduction of intramammary infection can continue to be realized.
Teat irritations, such as chapping or cracking of the teat skin can inhibit milk let-down which, in turn, reduces milk production and can cause an increase in mastitis. Teat dip before and after milking with a dip that disinfects and conditions skin.
Use germicidal dips that contain from 5 to 12 percent skin conditioners or the skin-conditioning equivalent. Teat washing with water in cold weather should be avoided because it removes the skin's natural oils and washing and drying can be abrasive.
If a dairyman desires to not teat dip, then it is even more important to pay extra attention to bedding, housing cleanliness and thorough drying of teats.
- Bedding. Ample amounts of bedding material should be placed in free-stalls. It is important to have good, dry bedding. Cows who are kept dry have a better chance of staying comfortable than those who stay wet during cold spells.
- Semen. Cold weather increases the danger of cold shocking of semen. Cold shock causes loss of motility, sperm metabolic activity and fertilizing ability of sperm. Cold shock occurs when semen is thawed and then subjected to cool or cold environmental temperatures before reaching the cow.
Inseminate the cow within minutes after semen has been thawed. The period of time between straw removal from liquid nitrogen and semen deposition in the cow should be as short as possible. If at all possible semen should be thawed and handled in a warm room or at least inside out of cold or subfreezing weather.