"Err.....no. Fats are triglyceride esters of long chain fatty acids. Short chain fatty acids really don't count. You're not going to build up body fat through absorption of acetic / propionic/ valeric / lactic acids (or their salts or esters) - which are what are produced in the rumen."
The three major VFA absorbed from the rumen have somewhat distinctive metabolic fates:"
Acetic acid is utilized minimally in the liver, and is oxidized throughout most of the body to generate ATP. Another important use of acetate is as the major source of acetyl CoA for synthesis of lipids.
Proprionic acid is almost completely removed from portal blood by the liver. Within the liver, proprionate serves as a major substrate for gluconeogenesis, which is absolutely critical to the ruminant because almost no glucose reaches the small intestine for absorption.
Butyric acid, most of which comes out of the rumen as the ketone beta-hydroxybutyric acid, is oxidized in many tissues for energy production.
"Fats are triglyceride esters of long chain fatty acids"
Well oddly enough having been a chemist for 44 years I know that.
Fatty acid synthesis is the creation of fatty acids from acetyl-CoA and malonyl-CoA precursors through action of enzymes......