Dealing with respiratory disease in young dairy calves 1

We know that respiratory disease is the second leading cause of death in un-weaned heifer calves (scours is the first). Unfortunately, heifers that experience respiratory disease also continue to have performance problems later in life. To effectively address these problem producers must address both the determinant and predisposing causes of respiratory disease.

Predisposing causes:

First what is the level of passive immunity being passed unto the calf? Currently guidelines are suggesting that baby calves receive 3-4 quarts of high quality colostrum within one hour of birth and 3 additional quarts within twelve hours of birth.

Quality of colostrum is important. Some producers are pooling colostrum to increase the diversity of pathogens the calf is exposed to. However, if you are doing this you also need to make sure to

not use colostrum from Johnes infected cows or first calf heifers. Secondly, storage of colostrum is important to minimize the growth of bacteria. Colostrum should be refrigerated or frozen as soon as possible after collection. Collecting colostrum under strict sanitary conditions is also vital to help minimize bacteria growth.

Utilization of pasteurized colostrum has also shown in research trials not to impede the availability of immunoglobulin’s (IgG) in colostrum while decreasing the mean total bacteria counts (Johnson et al. 2007). However, the pasteurization methods used should be heating of the milk to 60 degrees C for 60-120 minutes in a batch pasteurizer, which uses lower temperatures and longer heating time. This does not damage the immunoglobulin’s in the milk. Unfortunately, these types of pasteurizers can be quite expensive. Some producers will also use them to pasteurize their waste milk in order to offset the expense.

Cleanliness is critical to helping minimize risks. Clean and dry living environment is critical. Calves should not have shared housing with cows during the first week of life and should be removed from maternity pens as soon as possible. Cleanliness of the calving pen is also important to reduce microbe concentration.

We know that raising calves in barns is convenient and protects both the calves and employees from the environment. However, there are environmental risk factors that need to be addressed. The following should be used as a guide to reduce respiratory disease when using calf barns.

· Reduce microbial contamination in the pen via adequate sanitation

· Increase pen area (ideal: 32 square feet per calf)

· Avoid nose-to-nose contact between calves (solid separation panels if possible)

· Increase bedding depth

· Use cold-temperature housing

· Provide adequate ventilation while reducing drafts

· Provide additional nutrients via calf starter in cold-temperature housing.

Determinant causes:

We are assuming that calves have received adequate immunity via colostrum, so the next step is to reduce the microbial challenge. This means removing the calf from the dam as soon as possible. Calves should then be placed in their own individual pen avoiding nose-to-nose contact with other calves.

“Vaccines are now being marketed for prevention of clinical respiratory diseases. Traditional views have held that antibodies the calf receives through colostrum usually cause vaccines given to a young calf to be ineffective. More recent research indicates that, in certain instances, modified live viral vaccines stimulate a protective response in calves challenged with these agents. As example of this protection is the use of intranasal IBR/Pi3 vaccines in calves less than 1 month old” (Garcia & Daly, 2010). Vaccine programs for calves against respiratory disease should be developed in consultation with your veterinarian.

To learn more about the topic of respiratory diseases in baby dairy calves and to learn to apply a scoring system to calves with respiratory disease please refer to SDSU ExEx 4045 entitled Respiratory Diseases in Young Dairy Calves, written by Alvaro Garcia, Extension Dairy Specialist and Russ Daly, Extension Veterinarian at SDSU.