Fatty acids and fat supplements in lactating dairy cow rations

Abstract

In most Federal Milk Market Orders milk fat and protein yield are the major contributors to the price that producers receive for milk. The addition of supplemental fatty acid (FA)  sources to diets is a common practice in dairy nutrition to increase dietary energy density and to support milk production. The ability to understand and model FA, the effects of individual FA, and different FA supplements on production parameters has direct impact on dairy industry recommendations and the usefulness of FA supplementation strategies. The emphasis of the current paper is on biological processes and quantitative changes during the metabolism of FA in the rumen and the effect this has on FA availability to the dairy cow, the digestibility of these FA, and their overall impact on performance. We will focus on recent research supplementing palmitic acid (C16:0) and stearic acid (C18:0)-enriched supplements, on feed intake, digestibility, milk production, and milk composition, and energy partitioning.