It is crucial dairy calves are managed correctly to help reduce the incidence of disease. Poor health could negatively impact growth rates and their ability to meet the ideal 24 months calving target.
Read our handy checklist of factors that should be considered when rearing calves to give them the best possible start below:
Whether calves are housed in sheds, hutches or igloos, it’s vital their environment is carefully managed.
Overstocking calves will reduce the amount of airspace per animal and potentially increase the number of bacteria circulating in the air, leading to a higher risk of disease transmission. Upsizing pens from 2.3m2 to 4.1m2, for example, can reduce the total bacterial count by half.
Pen Size Requirements:
Many assurance schemes determine the minimum space requirement for calves. As a rough guide we recommend:
- A minimim of 1½ m2 per calf for calves less than 60kg (Newborn)
- A minimum 3m2 per cald when they get towards weaning
- A minimum of 4m2 – 5m2 after weaning
Top Tip: Grouping same age calves together, in a pen or shed, will also help to reduce disease occurrence and transmission.
Making sure calf housing is adequately ventilated with a constant flow of air is important. This will eliminate the amount of dust, contaminants, and pathogens that calves are exposed to, thereby reducing the risk of respiratory diseases such as pneumonia.
Adequate ventilation will also keep the environment at an ambient temperature and prevent calves from having to use valuable energy to keep warm. However, we should avoid air flow greater than 0.5 metres per second as this can cause calves to become too cold.
Bedding should be kept as dry as possible, as exposure to high levels of ammonia (<25 parts per million) can irritate calves’ mucous membranes and leave them more vulnerable to respiratory disease.
Straw is an ideal material for calf bedding, especially in the winter, as calves can nestle into it. This helps them to keep warm, meaning they are less susceptible to disease, and more likely to hit target growth rates.
Use the nesting score scale to help determine how much straw to provide your calves with. Aim for a nesting score of three, where calves’ legs are completely covered when lying down.
Nesting score scale
Avoid blowing straw or sawdust into calf housing as this creates dust which can irritate the respiratory tract and mucous membranes. This irritation can lead to permanent lung damage and increase the risk of respiratory disease.
It is important to consider the drainage within calf sheds or pens. Ideally, flooring should be pitched at a 5% gradient to allow urine and water to freely drain away. The more moisture that is retained in the building, the more heat will be drawn out and the colder the building will feel.
Calf coats can be used to keep calves warm in colder weather.
Consider using coats on newborn to one week old calves when temperatures are below 12oC. At this temperature and below, young calves will start to use valuable energy to keep warm, preventing growth and development.
For older calves, a farm protocol should be agreed on when coats should be used e.g. after three consecutive nights below 10oC.
Top tip: Make sure calves are dry before putting coats on and that they are cleaned from previous use. Jackets should also be taken off in the morning, once temperatures allow, rather than the afternoon. This is to allow calves to acclimatise to temperatures without the jacket, whilst the temperatures are typically higher than they are at night.
On-farm livestock biosecurity protocols are especially important when it comes to calves to reduce disease incidence and poor performance. Three key areas to consider are:
Make sure farms have established on-farm biosecurity protocols which all staff follow.
Additionally, remember bacteria can be brought into calf housing via boots, hands, and clothes. Boots and hands should therefore be washed and disinfected and, ideally, clothes changed or overalls worn before dealing with calves after being with other cattle.
Feed buckets should be cleaned and disinfected after use to minimise a build-up of bacteria. Here is an example of an equipment cleaning routine:
- RINSE: Use water at 32-38oC to remove dirt and milk residues. Do not rinse with HOT water. This causes proteins and fats to stick to surfaces, creating a breeding ground for bacteria
- SOAK: Use hot water 54-57oC mixed with chlorinated alkaline detergent (hypo chloride) for 20-30 minutes each time
- SCRUB: Use long handled brushes and gloves to remove any remaining residue
- WASH: The water must be higher than 49oC, to remove the residue scrubbed off
- RINSE: Use acid sanitiser (peracetic acid) as this lowers the environment pH to prevent remaining bacteria growing
- DRY: Moist conditions are ideal for bacterial growth, so raise the equipment onto drying racks to allow drainage. Hang stomach tubes vertically to drain out. DON’T stack buckets or leave to dry upside down on concrete floors
Pens should be cleaned, disinfected, and bedded regularly, ideally between changes in calves.
Individual pens should be mucked out and disinfected once a calf has been moved out of it, whilst group pens should be cleaned once the group has moved into new housing.
If calves are staying in their allocated housing for more than a few weeks at a time, pens should be cleaned out regularly and washed/disinfected when calves can be moved to another area.
Steam cleaning calf housing with calves still in can be detrimental to calf health, as the moisture in the shed can make the atmosphere cold and increase the risk of respiratory disease.