2. Farm Tour
When they arrive, Gretchen sees that few updates or changes have been made to the original farm structures. The milk house is small and cluttered with various items including tools, drugs, cleaning solutions and clothing. The tie-stall barn houses the milking herd and has poor lighting and ventilation. Cows are tied facing the walls on each side of the barn, and a walkway traverses the middle of the barn. A few calves are housed at one end of the tie-stall barn. Twice a day the cows walk by the calves on their way to the milking parlor.
Calf scours and respiratory disease are the two most common and costly diseases of dairy calves and are also the two disease conditions for which the most antibiotics are used in dairy calves1,2. For a discussion of calf scours, go to “Neonatal Scours, Antibiotics and Dairy Calves” in this website . For a discussion of bovine respiratory disease, go to “Introduction to Bovine Respiratory Disease (BRD) ”
Several abandoned calf hutches are just a few yards from the milk house. Gretchen recently learned in school that calf hutches are a good way to isolate calves from each other and from the older cattle to reduce their exposure to opportunistic enteric and respiratory pathogens [Note: Opportunistic pathogens are agents that can cause disease in the presence of the proper combination of contributory causes that are present on most farms.] Gretchen wonders if maybe Dr. Karl will attempt to convince Chuck to try using the calf hutches again, even if they may be more work.
Dr. Karl and Gretchen start looking at the calves. The bedding seems to have been recently changed – perhaps in anticipation of their visit. However, because the calves are dirty, Dr. Karl suspects that the level of sanitation for the calves has not been very good. The calves are not isolated from each other and are exposed to the milking herd twice a day when the cows take the concrete walkway to get to the milking parlor. Dr. Karl tells Gretchen that on previous visits he has told Mr. Erby to isolate the calves from each other and from the cows to prevent transmission of pathogens, but this clearly has not been done.
For further recommendations on proper colostrum feeding, please consult the APHIS Info Sheet “Colostrum Feeding.”4
Gretchen notices a 50 lb bag of milk replacer propped up next to the calf buckets. According to the label, the bag contains “Medicated Milk Replacer”. She reads the ingredients and sees that oxytetracycline and neomycin have been added to the milk-based ingredients “to aid in the treatment of bacterial diarrhea (scours).” She remembers from lecture that neomycin, oxytetracycline and chlortetracycline are the antibiotics most commonly added to medicated milk replacer. She asks, "Mr. Erby, do you always use a milk replacer that contains antibiotics?"