cold stress

 Hypothermia occurs when the body temperature drops well below normal 

In general terms, with cattle, 

mild hypothermia occurs with a body temperature of 30°C–32°C, (86°F–89°F), 

moderate hypothermia at 22°F–29°C, (71°F–85°F) and 

severe hypothermia below 20°C (68°F).

In winter season it's common occuring problem with cattle because of low rearing mangment.

Cold stress in cows can occur when frigid temperatures cause muscle shivering, increased heart rate, and deeper breathing. This can lead to an increased metabolism rate, which requires more nutrients and energy

signs of cold stress in cows

• Decreased water consumption
• Lower respiration and heart rate
• Delayed return of ovulation
• Hypothermia
• Feeling cold to the touch
• Dullness
• Agalactia (sudden and dramatic milk drop)
• Ataxia
• Falling over
• Profuse diarrhea

Farmer should know how to manage cattle in winter season

1. Animal should kept in closed place where there is good ventilation

2. No direct air flow which touch to animal

3.  If there is room heater available or fire things available than start to             warm place

4. Keep cows clean and dry. Wet coats have greatly reduced insulating properties and         make cows more susceptible to cold stress

Young calves are very susceptible to low temperatures. They are on highly digestible feed and are not yet ruminating so less heat is generated by digestion.

Temperature

During their first week of life and when temperatures plummet to less than 15°C, they’ll start using energy from feed to keep warm. High risk calves – those with a difficult birth and twins, will feel cold at higher temperatures.

By their fourth week, they’ll be more robust and won’t feel the cold until about 0°C. However, high moisture levels and draughts will dramatically increase their susceptibility to cold stress. Draughts of just 5mph will make calves feel 8-10°C colder.

How to Prevent Cold Stress

Have a plan for when cold stress is likely to happen, that’s when the ambient temperature drops below 15°C, or at a higher temperature for high-risk calves.

1. CALF FEEDING

• Make sure every calf receives adequate quality colostrum
• Step up energy intake; this can be done by increasing the amount of milk offered per day, see table 1. Increasing the oil content of the milk replacer from 16% to 20% has a negligible effect on daily energy intake

2. GENERAL HOUSING CONSIDERATIONS

• Reduce cold drafts whilst maintaining adequate ventilation. Provide effective barriers to drafts at calf-level and places for the calves to shelter – plastic and timber are better insulating materials than concrete and steel
• Put in place a system to drain moisture
• Ensure bedding is kept clean and dry and provide plenty of deep straw bedding; it provides them with a great deal of insulation and reduces body heat loss
• Keep bedding dry and clean – much of the insulation value of bedding is lost when it is wet

3. SPECIFIC INTERVENTION MEASURES

• Provide calf jackets
• Provide an external heat source close to calves

Finally, calves born on very cold days take longer to stand and suckle so they may not receive enough colostrum to ensure adequate transfer of immunity. Make sure they each receive a minimum three litres or six pints within three hours of birth – use a teated bottle or stomach tube.