Certain diets cause a marked reduction in milk fat production in ruminants. Commonly referred to as milk fat depression (MFD), the mechanism involves an interrelationship between rumen microbial processes and tissue metabolism. Numerous theories to explain this interrelationship have been proposed and investigations offer little support for theories that are based on a limitation in the supply ...

The study appraised the effects of Carotino oil on in vitro rumen fermentation, gas production, metabolism and apparent biohydrogenation of oleic, linoleic and linolenic acids. Carotino oil was added to a basal diet (50% concentrate and 50% oil palm frond) at the rate of 0, 2, 4, 6 and 8% dry matter of the diet. Rumen inoculum was obtained from three fistulated Boer bucks and incubated with 200...

Lipid metabolism in the rumen is responsible for the complex fatty acid profile of rumen outflow compared with the dietary fatty acid composition, contributing to the lipid profile of ruminant products. A method for the detailed dimethylacetal and fatty acid analysis of rumen contents was developed and applied to rumen content collected from lambs fed lucerne or concentrate based diets suppleme...

Diet-induced milk fat depression (MFD) continues to have major economic impact in the dairy industry and a priority for finding solutions. Current thinking links MFD with the formation of bioactive trans fatty acid intermediates produced from biohydrogenation of unsaturated fatty acids by the rumen microbial population. The most potent biohydrogenation intermediates linked to MFD include severa...

This paper focuses on dietary approaches to control intramuscular fat deposition to increase beneficial omega-3 polyunsaturated fatty acids (PUFA) and conjugated linoleic acid content and reduce saturated fatty acids in beef. Beef lipid trans-fatty acids are considered, along with relationships between lipids in beef and colour shelf-life and sensory attributes. Ruminal lipolysis and biohydroge...

An article we wrote for the 1998 Illinois Dairy Report (Can Milk Fat be Beneficial to Your Health?) provided a brief description of conjugated linoleic acid (CLA), a minor component of milk fat. Briefly, CLA is a fatty acid that is synthesized in the rumen during biohydrogenation of linoleic acid (C18:2), the predominant fatty acid in vegetable oils. The pathway of biohydrogenation is C18:2 ? C...

Oils derived from insect defatting may represent novel alternatives to expand the range of lipid supplements in ruminant feeding, both increase energy density diets and improve fatty acid (FA) profile milk meat through modulation ruminal biohydrogenation. Furthermore, chitosans might also modulate FA biohydrogenation, as indicated for crustaceans. Thus, this work was conducted assess potential ...