It is a pleasing sight to see some sun this week; however, with it comes some cold weather, which increases the risk of pneumonia in calves.

Temperatures dropped as low as 0℃ on Tuesday night, with frost in many places around the country.

Last night may have been a bit warmer, but temperatures are set to drop as low as -2℃ again tonight.

These swinging temperatures pose a significant risk for calves to contract pneumonia, especially as pens fill up deep into the calving season.

This is a serious threat considering pneumonia and calf scour remain the two biggest killers of young calves.

Studies have suggested that approximately 3% of calves born die from pneumonia within the first 12 weeks of their life as the inflammation of the lungs causes permanent damage.

Pneumonia

Cold weather itself never poses the biggest threat, as it can actually help in keeping disease at bay.

However the temperature swings are the main concern, which can go from freezing temperatures up to 11-12℃ in 24 hours.

Either way, farmers should keep an eye out for any initial signs of pneumonia, which may include:

Reduced feed intake;
Being ‘off form’;
Dullness, dropping ears;
Hollow sides;
Fever of over 39.5℃;
Cough;
Increased respiratory rate (later sign);
Watery discharge from nose and eyes (later sign).

Keeping an eye out for these symptoms is important as early detection is crucial in terms of the animals' survival.

If disease develops as far as the later signs, it is considered advanced. Even if the calf survives, its lungs will be damaged and it will never reach its full potential.

Where there are only one or two calves showing obvious signs of pneumonia, there is a likelihood that a few more in the group are in the early stages of infection.

However, if any calves are detected as sick, they should be treated and isolated on their own until recovery.

Vaccinating against pneumonia is recommended, but it is only part of the solution.

Farmers also need to remember that antibiotics are ineffective against viral infections, but in cases where bacterial involvement is suspected, antibiotic treatment is required.

Prevention

Pneumonia is caused by viral or bacterial infections, however poor colostrum intake, poor calf shed hygiene, poor ventilation, and overcrowding can all factor towards pneumonia.

In rare cases, lungworm may be causing pneumonia in young calves, and these calves will not respond to antibiotic treatment.

Calf housing need to be well ventilated, with plenty of air and no draughts. As well as that, the calves' bedding needs to be good and thick.

This should ensure calves are in an ambient temperature of at least 10℃, which is the absolute minimum temperature needed for dairy calves to thrive; as any lower, they will begin to burn their energy reserves to stay warm.

That is why farmers should be carrying out the ‘knee test’ to check bedding; if you kneel fully in the straw and your knees get wet/damp, then it is too damp for your calves.

If you are grouping calves, ensure to group them by age and size to make management and feeding easier.

Grouping also helps to keep the group stable, while you should make sure they have at least 1.5m² of lying space and an air space of 7m³/calf.