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Cold Stress in Dairy Calves and Cows

Winter weather costs animals energy that would otherwise go to growth, health and milk. Calves are most at risk, but cows need attention too.

How cold affects calves and cows

Animals burn extra energy to stay warm once they fall below the temperature range at which they are comfortable. Young calves have little body fat and a large surface area for their size, so they chill fast, especially when wet or in a draft.

Adult cows handle cold better, but wind, wet hair coats and muddy lots reduce their tolerance. A cow using energy to stay warm has less to give to milk and reproduction.

Signs of cold stress

Look for shivering, hunched posture, tucked-in legs, curled-up resting position and cold ears. Calves may be slow to get up, may drink less and may grow poorly. Frostbite on ears, tails and teats is a real risk in severe weather.

Check animals more often when temperatures fall or wind rises. A calf that is down and cold needs help quickly, and your vet can walk you through a warming plan.

• Shivering and hunched stance
• Calves slow to rise or eat
• Cold ears and tail tips
• Frozen teat ends or frostbite

Shelter, bedding and drafts

Dry bedding is the most helpful tool. Deep, clean straw that lets a calf nest in so that its legs are covered gives real insulation. Wet bedding strips heat away fast, so refresh it often.

Protect from wind but keep fresh air moving, since stuffy, damp air raises the risk of pneumonia. Calf jackets can help in some situations when used according to your vet's and extension advisor's guidance, but they must be kept clean and dry.

• Deep dry bedding changed often
• Windbreaks without trapping moist air
• Dry, well-drained lots
• Clean, dry calf jackets if you use them

Feed and water in winter

Animals need more feed energy in the cold. Ask your nutritionist how to adjust the milk or milk replacer program for calves and the ration for cows. Feeding more often or increasing amounts may help, but follow your advisor's plan.

Water must stay unfrozen. Cows drink less when water is icy, and calves need access to warm, clean water. Heated waterers must be installed safely, with grounded electrical components and regular checks for stray voltage.

• Review calf feeding plans before winter
• Provide ample forage for cows
• Keep water open and clean
• Check electrical safety of heaters and cords

Newborn calves in cold weather

Newborns need to be dried and given colostrum as soon as possible, within the first hours of life. A chilled calf cannot digest colostrum well, so warming and feeding go together. Your vet can teach staff how to warm a cold calf safely.

Avoid placing a very cold calf next to a heat source that could burn. Never leave heat lamps unattended, because they are a fire risk. Follow manufacturer and fire safety guidance.

• Dry calves right after birth
• Feed colostrum promptly
• Warm a chilled calf using a plan from your vet
• Avoid open-flame or unattended heaters

Teats, udders and cows

Freezing weather can hurt teat ends. Dry teats well after milking, use protection steps recommended by your milk quality advisor, and keep cows from lying in frozen manure or on icy surfaces.

Slippery footing causes injuries. Spread sand or other traction material in alleys and keep walkways open.

• Dry teats before cows go out
• Protect teat ends as advised
• Improve traction on ice
• Give cows a dry place to rest

Common mistakes

Relying on bedding that is damp, overlooking wind, ignoring frozen water, failing to feed extra energy and checking calves too rarely are common errors. Another is using heaters or lamps unsafely. Follow label or vet-set withdrawal times if any treatment is given to a sick animal.

More in Herd Health & Disease Management

• Fly Control on Dairy Farms
• Parasite Control Plans for Dairy Herds
• Internal Parasites and Milk Production
• Lice and Mites in Dairy Cattle
• Biosecurity for Small Dairy Farms
• Quarantine Protocols for New Dairy Cattle