Pneumonia in Calfs
As the cool, damp fall weather is coming, and winter is soon behind, a review of calfhood diseases and treatment, particularly pneumonia seems appropriate. As many of you have experienced over the years, fluctuating cool temperatures brings on an increase in stress level and disease in young calves. Pneumonia cases in particular are common this time of year, but scours and other issues also occur. As with many diseases, calf pneumonia especially, one cannot over emphasize the importance of prevention, prevention, prevention.
For young calves, this goes right back to colostrum management. You all have heard this many times, but ensuring the calf has received adequate, clean, quality colostrum as soon as possible after birth goes a very long way in the prevention of pneumonia, scours, navel infections, etc. Ensuring every newborn calf receives 4L of clean, high quality colostrum within 6 hours of birth will significantly decrease your risk of disease like pneumonia.
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But as you all know, prevention does not stop there. As the temperatures drop, calves require higher energy levels to maintain body temp and healthy immune function. The old standard of feeding calves 2L twice a day, while barely providing enough energy for growth during summer months, actually is a starvation diet in the winter. Calves will grow very poorly, and their immune systems are not provided enough energy to fight off infection pressures.
Some good rules of thumb when caring for calves in cold weather are:
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Provide ample bedding and an environment free from cold drafts.
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Provide free choice water even in below freezing weather (will encourage starter consumption and therefore provide more energy).
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Feed milk or milk replacer at body temperature to avoid calf having to utilize energy reserves to warm up milk to body temperature.
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Feed more energy in colder temperatures. Calves need to expend energy starting at approximately 10 C to maintain body temperature. Need 25-35% more energy at -4 C and 50-60% more energy at -18 C just to maintain body temperature.
Ways To Feed More Energy
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Feed whole milk (whole milk or transition milk contains about 25% more energy than 20:20 milk replacer.)
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Feed more of the same (can feed up to 3-3.5 L of milk replacer twice daily).
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Add extra feedings (smaller younger calves may not consume 3L per feeding so add an extra mid day feeding: 2L three times per day).
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Add more milk replacer powder in a gradual transition (increase the dry matter intake by adding more milk replacer powder for the same amount of water – mix up to 15 or 18 % dry matter instead of the usual 12.5% - will need free choice water for sure with this option and should be used with caution).
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Add extra fat (switch to special winter formula milk replacer such as 20:27 to provide the extra energy without an extra step).
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Feed milk or milk replacer at body temperature to avoid calf having to utilize energy reserves to warm up milk to body temperature. Feed more energy in colder temperatures. (See point 4 above).
Vaccination Program
A strategic vaccination program can also be of benefit in reducing the risk of calf pneumonia. Vaccinations are not for everyone, and certain protocols for one producer may not be necessarily effective or possible for the next. Ideal vaccine protocols are ones that are customized by the veterinarian to address a particular producer’s needs, management, calf flow, or even facility restrictions.
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Calf vaccinations are arbitrarily broken down into either pre- or post-weaning pneumonia.
Pneumonia that is occurring in pre-weaned calves can be difficult to control using only traditional injectable vaccines. A calf’s immune system is relatively immature at this stage of life and does not fully respond to an injectable vaccine. Although better than nothing, producers will still often struggle with calf pneumonia, especially younger calves with this approach.
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The intranasal product Inforce-3, which has been on the market for several years now, can be quite beneficial if experiencing pneumonia in younger calves. A 3-way modified live viral vaccine (IBR, PI3, BRSV), given intranasal as early as 1 day of age, is designed to stimulate local protection in the respiratory system without having to be processed by the calf in the same way as an injectable product. As such it avoids some of the shortcomings of injectable products in this age group of calves and can be given as early as day 1 of life. It should be noted that there has been reduced immune response to Inforce-3 when given between days 3-7 of life, so avoid administering it to calves in this age range.
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There is one other intranasal vaccine: Once-PMH, which protects against the bacterial causes of pneumonia (Mannheimia hemolytica and Pasturella multocida). It is usually given in conjunction with (but at least a week apart from) Inforce-3 at 1 week of age or older.
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Older calves will often experience pneumonia at or shortly after weaning. This is often in conjunction with the stress of weaning, a potential pen move or even different barn, and co-mingling with other calves for the first time. The intranasal Inforce-3 or Once-PMH can be boostered in these post-weaned calves about 8 weeks after their initial dose. Older calves closer to 6 months of age should get an injectable 5-way vaccine whether it be killed (Triangle), or modified live (Bovishield, Express) vaccine, that also has the reproductive/fetal protection benefits as well as the pneumonia protection.
Unfortunately, despite all of the above measures, in some cases it is not enough and calves will still experience pneumonia. There are many different approaches and products available for the treatment of pneumonia and the particulars are best discussed with your herd veterinarian as a complete discussion would be beyond the scope of this newsletter. Available antibiotics can be classified as short acting (requiring daily treatment), long acting, and ultra-long acting. Not surprisingly, the convenience of the ultra-long acting product comes with a financial trade off as many of these products are more expensive. The decision of which to use may depend on factors such as previous treatment success or failure, cost, convenience, or handling facilities. Again, your veterinarian can provide some valuable advice on which products and other supportive care might be best for you.
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Vaccine Handling and Storage
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A review and reminder of the proper handling and storage of vaccines is appropriate. Every year we are made aware of incidences of “accidents” that occur with the storage and handling of vaccines. Fridges on farms can fail but more commonly they aren’t working at the correct temperature range for vaccines. The proper temp range is 2-7° Celsius and most vaccines can’t handle freezing or too warm temperatures. A hi/lo thermometer in the fridge will help you monitor the temperature and alert you to extremes that are detrimental to the vaccine. Some vaccines can handle a wider range than what is on the label, but most are not effective after being outside the recommended range. Vaccines should also be stored at the back of the fridge, not on the door, so that they don’t experience the temperature swings that come with opening and closing the fridge.
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Handling is also important. When picking up vaccines we recommend going straight home or using a cooler. We can provide an ice pack if you aren’t going directly home. Ordering vaccines to the Wellesley night box is not recommended, but if it must be picked up there instead of our Milverton office, make sure to ask for the vaccines on ice and confirm the timing of its placement in the night box. If accidents do happen, be sure to report to the clinic and we can call the technical services department at the vaccine company to determine whether the product is still usable.