It's best to work out a specific program for your farm in consultation with your veterinarian to make sure that the program is designed to meet the specific needs of your herd. There is some general information that all producers should know about preventing diarrhea in calves. In calves, scours is usually caused by any of several infectious agents, including bacteria, viruses and protozoa.
Common viruses are bovine rotavirus and bovine coronavirus.
Often diarrhea is caused by infection with more than one of these causes acting together. In some outbreaks, the scours is caused by different infectious agents. The bacteria, viruses and protozoa that cause diarrhea are usually carried by adult cattle who contaminate the barn with their manure. The balance between the calf's immunity or it's ability to resist infection and it's exposure to the bacteria, viruses and protozoa that cause diarrhea determines whether it develops scours or not. Scour prevention programs are made up of strategies aimed at increasing the calf's ability to resist the infection and at reducing the calf's chances of becoming infected.