Jim Reynolds, of the Veterinary Medicine Teaching and Research Center in Tulare, Calif., offers these tips to troubleshoot biosecurity problems with calves. To read more from Jim Reynolds, see: "Troubleshoot biosecurity problems"

“Calves born on dairies are either raised on the dairy or sent to calf ranches. Calves raised on the dairy are usually moved from the maternity area to the calf raising facility. All areas and things that the calf contacts must be clean, especially the trailer used to move calves.

“For calves raised on the dairy, incoming biosecurity begins in the maternity area. Calves must be born into clean, dry bedding and kept warm. Calves must be fed colostrum as soon as they are able to nurse and the colostrum must be clean and not contaminated. The trailer or cart used to transport them to the calf raising area must be cleaned and sanitized daily.

“The dairy must not have the maternity area commingle or be too near the hospital cows. Sick cows and close-up and calving cattle cannot interact or the probability of spread of pathogens from the hospital cows to the newborn calves increases. The calves will then take the pathogens from the maternity area to the calf facility.

“Dairies often have outside trucks and trailers haul cull cows and bull calves away. These vehicles are real sources of pathogens and must be clean. Cull cows must be loaded away from the maternity and calf raising area. Calves sent to calf ranches are usually kept in holding pens for at least one day until the calf hauler comes. These calves must be fed milk or milk replacer if they are to be held for 12 hours or longer to maintain body condition and manage the infectious dose principle and for the welfare of the calves. The trucks and trailers must be clean and dry and provide bedding so that the calves do not slip when standing and have comfortable material to lie on. The calves cannot be over-crowded in the vehicle and must have enough space to lie comfortably without lying on each other.

“The calf facility must be fenced to keep dogs and cats away as much as possible. There should be only one common entrance and on large facilities it should be guarded. The calf ranch should have signs that direct visitors to the office (outside the fence). In other words, all visitors should be directed to the office and away from the calves. Only workers and pre-screened people should be allowed into the farm.

Source: Dairy Calf and Heifer Association