Decreasing bovine respiratory risk in calves

By Noah Litherland, Ph.D., Vita Plus dairy technical specialist

Bovine respiratory disease (BRD) is considered a primary health challenge on farm, requiring individual calf treatment. Symptoms of respiratory disease are not always observable, especially in the early stages of growth, and are influenced by stressors such as weather or pen changes. Diet changes decrease immune defense and open the door for viruses to further suppress immune function and then increase opportunities for pathogenic bacteria to invade respiratory tissues.  Vaccination to address viral causes of BRD often helps.  The effectiveness of antibiotic treatments is dependent upon timing of delivery and sensitivity of the pathogen.

Consider the following proactive management strategies to prevent BRD on your farm:

Maternity and colostrum

1. Keep calving pens and the surrounding maternity area clean.
2. Remove calves from dams within 30 minutes of birth.
3. Feed quality colostrum (Brix greater than 22%) from vaccinated cows. Feed 3 to 4 quarts of first-milking colostrum for the first feeding and 2 to 3 quarts of second-milking colostrum for the second feeding.
4. Heat-treat colostrum at 140 degrees Fahrenheit for 60 minutes to limit pathogen transfer and increase the efficiency of IgG absorption.
5. If colostrum is inadequate in terms of quality and/or quantity, feed a high-quality colostrum replacer.
6. Kink esophageal tube during insertion and removal to limit risk of aspirating colostrum or colostrum replacer.

Newborn calf

1. Towel-dry calves after birth to fluff the hair coat, allowing it to serve as a boundary layer to better insulate the calf and keep it warm for the first 24 hours. This can increase colostrum IgG absorption and decrease energy loss.
2. Keep surfaces clean, including worker hands.
3. Under the direction of the attending veterinarian, use an intranasal vaccine to protect calves from BRD-causing viruses and bacteria.
4. Dehorn calves within the first day after birth to reduce the stress of dehorning at a later age.
5. Focus on training calves to drink milk from a bottle with a small nipple opening for meals three through six and then continue to feed from a bottle or pail train.

Nursery environment

1. All-in/all-out animal flow decreases the risk of spreading BRD pathogens across multiple age groups and allows cleaning time between groups of calves.
2. Place a drain under bedding to limit moisture accumulation.
3. Air exchanges with positive pressure tubes and/or exhaust fans should be six to eight air changes per hour.
4. Minimize interaction with manure, including manure storage facilities.
5. Bed with straw or coarse shavings. Fine particles (specifically from sawdust) are associated with increased risk of BRD.
6. Research conducted in Belgium showed the greatest risk for seasonal BRD in calves is October through March. Air quality and energy balance are likely key factors.

Nursery nutrition

1. Provide calves with an adequate plane of nutrition from milk and starter.
2. Energy, specifically glucose, is needed by the immune system to clear respiratory infections.
3. Provide calves with adequate vitamin and trace mineral nutrition. Important minerals include selenium, vitamin A and vitamin E.
4. A moderate immune response requiring 200 grams of glucose per day (8 grams per hour) is enough energy to decrease a calf’s growth rate by an estimated 0.5 pounds per day.
5. Milk osmolality of 280 to 400 osml/L and milk additives (such as plasma, medium-chain fatty acids from coconut oil, yeast cell wall and direct-fed microbials such as Bacillus subtilis) increase intestinal integrity.
6. Providing warm drinking water (105 degrees Fahrenheit) 10 minutes after a milk feeding or in the middle of the day between milk feedings provides calves with the most essential nutrient to hydrate and maintains blood pH and digestive osmolality.
7. Feed to maintain intestinal barrier function to consistently produce firm and dark manure.
8. Calves with liquid and/or white manure are at risk for decreased intestinal integrity.
9. Give scouring calves electrolytes.

Early recognition and treatment of BRD

Changes in feeding behavior are the first sign a calf might be developing BRD.  Calves that are slow to finish or do not finish their milk or that lie down immediately after drinking milk are candidates for further evaluation. Other indicators are elevated temperature (more than 102 degrees Fahrenheit), elevated respiration rate, loose manure, nasal discharge, lethargic behavior and standing in a hunched position.

Work with your veterinarian to develop a treatment protocol. A lung ultrasound is a proactive strategy to identify calves with lung consolidation early in the BRD process and to determine if antibiotic therapy was successful in bringing the calf’s respiratory tract into a healthy state.

Weaning and post-weaning

Starter grain drives gastrointestinal tract development and metabolizable energy and protein for maintenance and growth.  For example, a calf consuming about 5 pounds of starter grain is eating about the same amount of digestible dry matter as a calf consuming 3 gallons of 13% solids milk.

Gradual weaning over two weeks is preferred over one week or abrupt weaning.  Avoid making more than one change per week. Make the transition to cool water in the nursery phase or provide calves with warm water for the first week after transitioning out of the nursery.  Both dehydration and decreased energy intake can make transition calves more susceptible to BRD.

Post-weaned calves require good bedding and thermal support, especially in the winter.  While post-weaned calves are larger and can likely tolerate more thermal challenge than nursery calves, they should still be bedded to keep them dry and allow them to nest into bedding, especially in the first week following a pen move.

Brainstorm with your management team or reach out to your Vita Plus consultant to find opportunities to decrease the risk of BRD on your farm.