Cold Weather Feeding Guidelines for Manitoba Cattle

Manitoba cattle face prolonged cold, wind, and sudden weather events. Managing nutrition, body condition, and shelter is essential to help cattle maintain body temperature and avoid the significant performance losses associated with cold stress.
 
1. Understanding Lower Critical Temperature (LCT)
The lower critical temperature (LCT) is the point at which cattle must increase heat production to maintain normal body temperature. The LCT is influenced by body condition, weight, diet, coat depth, and weather conditions.
Wind and moisture increase cold stress
Effective temperature is reduced when cattle face:
  • Wind
  • Wet hide from rain or melting snow
  • Storm exposure
Example:
A temperature of –5°C with 40 km/h wind ≈ –20°C no wind.
 
2. LCT Values by Animal Type
Animal Class
Lower Critical Temperature (LCT)
Dairy cows & feedlot cattle (high-grain diets)
–30°C to –45°C
Pregnant beef cows, dry dairy cows, growing calves
–10°C to –25°C
Newborn calves (0–3 weeks)
+13°C
Dairy calves (3 weeks–weaning)
+1°C
Thin beef cows (BCS 1–2)
~–17°C
Cows in good condition (BCS 3+)
~–25°C
Key message:
Cattle with better body condition tolerate cold markedly better.
 
3. Managing Acute Cold Stress
During short-term extreme cold snaps:
  • Provide windbreaks or shelter
  • Increase energy intake, typically with grain
  • Ensure cattle have adequate fat reserves
  • Separate and provide extra feed to thin cows
These steps help cattle maintain body temperature without severe stress or health impacts.
 
4. Acclimatization to Winter Cold
The long-term effects of winter cold are more significant than short-term weather events.
When temperatures remain below the thermoneutral zone (15°C–20°C):
  • Hair coat thickens
  • Metabolic rate increases
  • Dry matter intake can rise by up to 30%
  • Forage digestibility decreases because feed moves through the gut faster
Energy Requirement Adjustment
Energy needs increase by ~10% for every 10°C drop below the comfort zone.
Example:
A cow normally requiring 100 units of energy would need ~130 units in sustained cold.
Feeding response
  • Cows in good condition can increase hay intake by up to 10 lb/day, but only to a limit.
  • Beyond that, energy must come from grain or higher-quality forage.
 
5. Dairy Cow Considerations
Milking dairy cows:
  • Are usually housed indoors
  • Receive high-energy diets
  • Are less affected by cold stress
However, acclimatization may increase DMI by 2–3 kg/day.
If cows are already at maximum intake, milk production may drop unless energy density is increased.
Dry dairy cows and replacement heifers respond to cold similarly to beef cattle.
 
6. Practical Management Recommendations
Provide shelter
  • Windbreaks, natural or constructed, reduce effective temperature dramatically.
Monitor body condition
  • Thin animals have higher LCTs and greater energy needs.
Increase energy in cold weather
  • Add grain when forage intake alone cannot meet increased requirements.
Group management
  • Feed thin cows separately to ensure adequate intake.
Plan for forage quality loss
  • Cold weather reduces forage digestibility—energy supplementation becomes more important.