By Grant Dewell, Iowa State University
Calf diarrhea, also known as scours, is the second leading cause of death in neonatal calves. Scours prevention focus on two key areas: the health of the calf and cleanliness of the environment. Optimal calf health is achieved through proper care of the cow prior to calving and ensuring adequate intake of colostrum at birth. The pathogens that cause neonatal diarrhea are transmitted by fecal-oral contamination. One of the easiest routes of transmission is from contaminated mud/manure on the cow’s udder that is ingested by the calf when it nurses.
As the calving season progresses the number of pathogens increases exponentially as young calves become exposed, infected, and begin to shed large numbers of pathogens. Calves that are 7 to 14 days older then new born calves can be a major source of pathogens. Rotational calving areas such as the Sandhills Calving system control calf diarrhea by limiting the buildup of pathogens in the environment where the most susceptible calves are.
Sandhills calving system
A method to manage pathogen/disease exposure is to implement the Sandhills Calving System which incorporates use of multiple calving areas on pasture. Cows are calved in a calving area, and after 7-10 days the pregnant cows are moved to a new area to calve and the pairs are left behind in the area that they calved in. The next group of cows then calves in a fresh clean environment for 7-10 days, and then moves on. This management system prevents older calves that may be shedding higher levels of pathogens from exposing young at-risk calves.
Although the Sandhills system has been shown to be very effective at controlling calf scours, it may not be easy to implement in operations that do not have a large land base to utilize. This system requires 6-8 calving areas to move to and may not be practical to implement in smaller farms or operations that lease ground and cannot justify expenditures for water supply, shelter, and other costs.
Modified Sandhills system
A modified Sandhills system can be implemented that can help prevent calf scours outbreaks. A modified system should have three calving areas available. Calving areas can include calving barns, dirt lots, and pastures. Movement of pregnant cows to the next calving area can either be timed or in response to disease. A set, timed move should happen every 20-30 days. Although this does not protect every calf from exposure to disease, it often breaks the cycle enough that a scours problem can be managed instead of getting out of control.
The other option is to use your primary calving area until calf diarrhea starts and then move your pregnant cows to a new calving area. With this management system you may be able to calve some years in the same place all season without problems. If problems with scours arise, you have planned options of where you will move your cows to protect the calves that are yet to be born.