Making small adjustments to the layout of calf housing can help streamline the feeding and herding processes, and small improvements to ventilation can help reduce the risk of respiratory disease outbreaks.
Bovine respiratory disease (BRD) can have a detrimental impact on livestock, and farmers should take all possible steps to avoid outbreaks in their herd.
Design project engineer for UK-based company, Galebreaker, Scott Gearon said:
“Even if a dairy calf overcomes an infection of BRD, there’s a lifetime cost of £722 due to the cost of treatment, delayed first calving and reduced yields in the first and second lactations.
“BRD can also have a serious impact on beef calves, with losses of up to 6kg/month in live weight gain in animals who were infected, and an overall decrease in carcass weight of 21kg,” he said.
Poor ventilation within calf housing is a key factor in BRD infections, but Gearon said that changes can be made to existing housing ahead of spring calving to reduce infection rates.
“Now is the time to think about how you can improve ventilation within existing housing to reduce the level of respiratory diseases in young stock to protect your productivity next year,” he added.
It is common practice on many farms to use older sheds to house calves, but careful thought should be given to ventilation.
Unless the necessary improvements are made to ventilation, farmers could unknowingly be subjecting calves to higher levels of pathogens in the air, temperature fluctuations and draughts.
“Keeping air constantly cycling through your young stock housing will help reduce the concentration of airborne pathogens and harmful gases in the air.
“We measure the fresh air inside a building by looking at the number of air exchanges that take place, which is when the air within a building is completely replaced. The target range in the winter is six-to-eight exchanges/hour,” Gearon explained.
He said the first step to enhancing ventilation, is to assess the existing airflow within the building, and noted that “this will provide a starting point from which to improve”.
“The best way to understand the airflow within the building is with a smoke test. This will give a visual representation of how the air moves through the unit,” he said.
Ventilation guidelines
“Use smoke pellets or smoke bombs throughout the housing and watch where the smoke goes. The smoke should clear within two-three minutes, and you should see the smoke rising through a ridge at the top or leaving through the sides of the building.
“Ideally, air inside the housing should be moving at 0.2m/second at calf height – anything over 0.3m/second is classed as a draught, whereas anything below 0.12m/second is counted as still air.
“Seeing animals avoiding an area of a building could be a sign of a draught. This can be fixed by using a rubber draught excluder at the bottom of gates or creating windbreaks,” Gearon explained.
Gearon also recommended using a positive pressure tube ventilation (PPTV) system: “A PPTV system can provide controlled ventilation by bringing fresh air in and forcing it along a tube with holes that angle air directly where your calves need it most,” he said.