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The benefits of tributyrate in calf milk replacer

Amanda Kerr for Progressive Dairy Published on 30 April 2021

As a major energy source, fat is an important element to consider in a calf milk replacer. Fat, however, has other nutritional effects beyond being a source of energy. Butterfat offers a unique fatty acid, namely butyric acid.

Extensively studied in animal and human research, butyric acid is an interesting short-chain fatty acid. The use of butyrate products in humans has shown to be effective in improving intestinal health of individuals compromised with health conditions such as Crohn’s disease.



Available butyrate products for animal feed are commonly in a salt form and pose a handling challenge due to smell. In salt form, sodium or calcium is loosely bound to a butyric acid molecule, and when dissolved in water, it disassociates from butyric acid at varying rates. However, the use of butyric salts in calf milk replacers has shown inconsistent results. This is likely due to the type and dose of butyrate salt, site and extent of release of the butyric acid molecule, with a minimal amount of butyric acid released lower in the gastrointestinal tract (GIT).

Lipases are enzymes that break down molecules of fat, with activity varying depending on the type of fatty acid and its position on the triglyceride. Butterfat contains butyric acid on the third chain (or “end” position) of a fat molecule. Calf salivary lipases are specific to cleave off the third molecule of butyric acid from a fat, and this happens quickly after consuming milk.

In the case of tributyrate (three molecules of butyrate composing the fat), this leaves two molecules of butyrate attached to the glycerol backbone to enter the small intestine where butyrate can impart a biological effect lower in the GIT. The release of one more butyric acid in the small intestine by pancreatic lipases will have a direct effect on cells in the lower GIT. The use of tributyrate in a calf milk replacer has received much less attention in research compared to salt forms of butyrate.

Innovative technology is required in order to deliver tributyrate in a commercial feed. Grober Nutrition Inc. evaluated the use of a proprietary encapsulated form of tributyrate in a calf milk replacer. Overall, there were no differences found for pre-weaning growth or calf health when supplementing the milk replacer with tributyrate. However, interesting results were found regarding starter intake and feed efficiency. Calves fed a milk replacer supplemented with tributyrate tended to have greater starter intakes and improved feed efficiency (Table 1).

Summary of data obtained when supplementing milk replacer


This is particularly important as jointly improving nutritional intake from milk and solid feed pre-weaning has long-lasting benefits into a heifer’s first lactation, not to mention the immediate benefit of a smooth weaning transition.

Considering the use of supplemental fatty-acid products is therefore of relevance to calf nutrition and can be another tool to improve gut development, integrity and feed efficiency. Butyric acid can exert positive biological effects such as enhanced gastrointestinal development, more robust epithelial structure in the gut and a shift of the gut microbiome to a more healthy population. Timing, dose and utilization of the correct type of butyrate product influences the extent of benefits seen. end mark

PHOTO: Mike Dixon.

References omitted but are available upon request. Click here to email an editor.

Amanda Kerr is a nutritionist with Grober Nutrition Inc.