Calves are born without immunity to help fight diseases. Early on, calves are left vulnerable to common on-farm microorganisms such as bacteria that cause E.coli and Salmonella, as well as viruses and parasites that cause illnesses such as scours and pneumonia.
We've already shown how excellent colostrum management is essential to boost calf immunity while their own immune systems develop during the first critical weeks of life. However, keeping the calf environment clean is also vital to reduce the risk of infection.
Poor environmental conditions can have negative effects on immune status due to increased energy demands and stress, and research has shown that stressed calves will have an even more compromised immunity.
Calves spend 75% of the time lying down so it's no surprise that bedding can play a huge role in ensuring a healthy calf.
Research out of the University of Wisconsin-Madison looked at the correlation between respiratory disease and calf bedding. To do this they developed a “Nesting Score” system to study the results of different bedding volumes used. The results showed that a nesting score of 3 dramatically reduces the prevalence of bovine respiratory disease in young calves.
Calf respiratory diseases can drastically reduce average daily gain (which in turn drastically reduces adult milk yield) and is also associated with lowered productive life. By reducing calf respiratory diseases you will reduce costs and help ensure a vital and high-performing adult cow herd.
One way to achieve this is through proper ventilation in your calf barn.
The key to a properly ventilated is calf barn is the proper installation of positive pressure tubes. It has been found that natural ventilated stables with properly installed positive pressure tubes see 50-75% reduction in calf respiratory problems.
Producers are often advised to house young calves individually to reduce illness. However, research shows an increased risk of illness only when groups are large (with more than 7-10 calves). Epidemiological surveys of hundreds of dairy farms in the US and Sweden found that the risk of respiratory disease and mortality is the same in small groups as in individual housing but are higher in large groups. Risks of diarrhea are similar in individual housing and in groups.
The health of calves kept in small groups (< 7-10 calves) is as good as that of calves housed individually. There is no evidence that group housing increases the risk of diarrhea. The risk of respiratory disease and mortality can be higher when groups are large.