Rumenic acid, also known as bovinic acid, is a conjugated linoleic acid

Conjugated linoleic acid

Conjugated linoleic acids are a family of at least 28 isomers of linoleic acid found mainly in the meat and dairy products derived from ruminants. As the name implies, the double bonds of CLAs are conjugated, with only one single bond between them....

 (CLA) found in the fat of ruminant

Ruminant

A ruminant is a mammal of the order Artiodactyla that digests plant-based food by initially softening it within the animal's first compartment of the stomach, principally through bacterial actions, then regurgitating the semi-digested mass, now known as cud, and chewing it again...

s and in dairy product

Dairy product

Dairy products are generally defined as foods produced from cow's or domestic buffalo's milk. They are usually high-energy-yielding food products. A production plant for such processing is called a dairy or a dairy factory. Raw milk for processing comes mainly from cows, and, to a lesser extent,...

s. It is an omega-7 trans fat

Trans fat

Trans fat is the common name for unsaturated fat with trans-isomer fatty acid. Because the term refers to the configuration of a double carbon-carbon bond, trans fats are sometimes monounsaturated or polyunsaturated, but never saturated....

. Its lipid shorthand name is cis-9, trans-11 18:2 acid.
The name was proposed by Kramer et al. in 1998. It is formed along with vaccenic acid

Vaccenic acid

Vaccenic acid is an omega-7 fatty acid. It is a naturally occurring trans-fatty acid found in the fat of ruminants and in dairy products such as milk, butter, and yogurt. It is also the predominant fatty acid comprising trans fat in human milk....

 by biohydrogenation of dietary polyunsaturated fatty acid

Polyunsaturated fatty acid

Polyunsaturated fatty acids are fatty acids that contain more than one double bond in their backbone. This class includes many important compounds, such as essential fatty acids and those that give drying oils their characteristic property....

s in the rumen

Rumen

The rumen, also known as a paunch, forms the larger part of the reticulorumen, which is the first chamber in the alimentary canal of ruminant animals. It serves as the primary site for microbial fermentation of ingested feed...

.
It can be considered as the principal dietary form, accounting for as much as 85-90% of the total CLA content in dairy products.

Biological properties

Laboratory studies indicate that rumenic acid shows anticarcinogen

Anticarcinogen

An anticarcinogen is any chemical which reduces the occurrence of cancers, reduces the severity of cancers that do occur, or acts against cancers that do occur, based on evidence from in vitro studies, animal models, epidemiological studies and/or clinical studies.Preventative anticarcinogens act...

ic properties.