More Acetate Equals More Milk Fat: Ingredients for Milk Components
Dairy producers get paid in two main ways – by producing a greater milk volume, or by producing more milk components. Milk protein and milk fat are these two components, and the pricing scheme can be read about here. It’s complicated, but the main idea is that producers want to produce more milk and components every day from their cows.
Complicating all of this is that everything a dairy cow consumes enters the rumen, a massive microbial fermentation vat that alters everything. The rumen bacteria, viruses, and protozoa consume some of everything for their own needs. These microbes, in turn, produce volatile fatty acids, namely acetate, propionate, and butyrate, that are absorbed and provide energy for the cow. But another important function should be mentioned here – volatile fatty acids are precursors for milk components. In this blog, the focus will be on milk fat.
A recent study sought to understand these relationships better. The study fed different levels of acetate and butyrate to dairy cows and measured several responses. While feeding more butyrate caused shifts in rumen pathways, and other responses, butyrate could not be demonstrated to increase milk fat production. If anything, the opposite was true. So, a situation where you produce more butyrate in the rumen would not be helpful to increase milk fat.
Conversely, more acetate in the rumen resulted in a greater amount of milk fat. This study and others proved that acetate is the precursor needed for more fat production in milk.
This is an interesting finding considering that ExPress® soy meal, a better soy ingredient from the high-shear dry extrusion process (using Insta-Pro equipment), has been shown to enhance rumen fiber degradation, and numerically increase rumen acetate, while numerically decreasing rumen butyrate. Likewise, the amount of daily milk fat production was numerically increased as well.
Better versions of commodity ingredients can have many benefits for dairy producers.