When calves bloat, it can be frustrating to handle and confusing to further prevent. But controlling feeding procedures to be consistent and accurate is your best protection, pinpointed Brian Miller, D.V.M., in a recent Dairy Calf and Heifer Association webinar.
What is abomasal bloat?
Most people who work with calves are familiar with what a bloating calf looks like — sudden abdominal distention on one or both sides like the calf has swallowed a basketball, possibly accompanied by lethargy, abnormal manure, teeth grinding, kicking at the stomach (colic), and even abrupt death. Sometimes with no apparent predisposing signs, a calf will show up sick and uncomfortable. Without action, death loss among bloated calves may easily reach 50 to 60 percent.
This bloat is most prevalent in calves under 3 weeks old, when the abomasum is around 70 percent of stomach volume. What exactly makes the wall of the abomasum become inflamed is unknown, but Miller presented a multifactor cause theory that places blame on:
• An explosion of gas-producing bacteria (mostly Clostridium perfringens types A and C)
• More fermentation of carbohydrates (like when calves are on a higher plane of nutrition)
• Slower emptying of the abomasum into the small intestine (such as when bigger meals are fed, or a milk replacer is too concentrated from not being mixed effectively)
Of course, feeding more milk or milk replacer is helpful in growing calves that will be productive sooner, and the practice has become more prevalent. To this fact, Miller recognized that “Volume isn’t the problem as long as the quality is there.”
Providing that quality milk encompasses multiple aspects. It goes without saying that all milk or milk replacer preparation equipment must be thoroughly clean. Miller also recommends using a Brix refractometer to measure total solids and evaluating any waste milk before it’s fed. Milk replacer must be mixed in the correct ratio.
Once you have the right milk to deliver, ensuring consistent feeding can make all the difference in preventing bacteria and fermentation enzymes from running rampant on the calf’s stomach. Each calf should receive:
• The same quality milk as the one before it. Testing and proper handling will make sure that, from the first calf to the last, total solids and temperature of the milk remain desirable. Brix readings of more than 1 to 2 percent variation can indicate a milk replacer mixing error.
• An appropriate amount of milk. The exact amount will depend if you can feed twice or three times a day, but Miller recommends possibly avoiding large volume feedings. If you do use a more intensive feeding program, try acclimating calves to the larger meals earlier in life to keep their diet consistent. Ongoing research suggests that a “step-up” program may not be necessary.
• Feed at consistent times. Normal intervals can help the digestive system process milk efficiently.
• Water. When delivered 20 to 30 minutes after milk, it can help with digestion.
Additionally, abomasal bloat is the same as any calfhood disease in that quality colostrum feeding and effective dry cow management will provide calves with immune function to ward off the gut infection. Clostridial perfringens may also be vaccinated against, both in the dam (with a precalving scour vaccine that will also protect against E. coli, Rotavirus, and Coronavirus) and in the calf (beginning at 3 to 4 months old).
If a calf becomes bloated, be sure to not feed it any more milk or electrolytes, as this may exacerbate the problem. Call your veterinarian so they can relieve the bloat with a stomach tube, an ultrasound needle tap, or IV fluids.
In a case where abomasal bloat becomes a regular problem on a farm, Miller recommends having your vet observe the calf-feeding process. A fresh set of eyes could help identify a cause, and a solution can be put into place.
Maintaining calf health takes work, but calves love consistency. Doing the simple things correctly, every day, will go a long way.