Prevention of abomasal bloat in dairy calves


Well, it’s that time of the year when stomach emptying is critical for relieving the misery from overeating at a family meal, and of course, being able to eat another big meal in 4 hours at the next family member’s house.

Satiety is influenced both by chemical signals (e.g. glucose and fatty acids in the blood) and gut fill (distension of the stomach). And of course, sometimes we don’t respect these signals.

We eat because it is expected of us (it’s grandma’s house, etc), we like the taste, it fulfills an emotional need, etc.

By now, you thought that you had misread the title of this article — actually not.

The human stomach is similar to the abomasum in ruminants. In young calves with intake of milk, the esophageal groove closes to allow milk to divert directly to the abomasum.


In the January 2017 issue of the Journal of Dairy Science (yes, I know its still 2016, but the Journal comes out the month previous to the “issue date”), there was a review article on abomasal emptying in dairy calves and how it may be associated with gastrointestinal disease.

One of the potential associations is delayed emptying of the abomasum is thought to possibly increase the risk for abomasal bloat. Abomasal bloat has been dreaded among dairy farmers for several years.

Even though the incidence may be low within a herd, mortality is high. Once a calf shows signs of abomasal bloat, there is only a short time for response, treatments suggested vary, and success is limited.

The exact cause of abomasal bloat in dairy calves remains unknown. From a survey conducted by Ohio State researchers, a trend based on herd size, breed, or season could not be established.


Also, no single diet type or feeding method emerged as a risk factor for abomasal bloat.

From other studies, some risk factors suggested include high-osmolality milk replacers, improper mixing of milk replacers, a large volume of milk being fed in a single daily feeding, cold milk (or milk replacer), water not being offered to calves, erratic feeding schedules and failure of passive transfer.

A bacterial etiology has been suggested for abomasal bloat, with the bacterial pathogens suspected including Clostridium perfringens, Campylobacter and Sarcina species.

An experimental induction of abomasal bloat in calves was successful at Oklahoma State University by drenching Holstein calves less than 10 days of age with a carbohydrate mixture containing milk replacer, corn starch, and glucose mixed in water to provide a meal with excessive fermentable carbohydrates.

These authors proposed that this syndrome involves excess fermentation of high-energy gastrointestinal contents in the abomasum (from milk, milk replacer, or high-energy oral electrolyte solution), along with the presence of fermentative enzymes (produced by bacteria) that lead to gas production and bloat.

On your farm

The cause of abomasal bloat is likely multifactoral. The authors of the review article concluded that it’s cause likely involves both bacteria that produce gas as well as something that slows abomasal emptying.

If abomasal bloat is occurring on your farm, one of the first things that should be examined is the precise details of the nutrition program, especially the milk feeding.

However, sanitation and vaccination practices also should be reviewed.


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