InspireCows has launched a NEW VIDEO explaining where milk fats come from and how to deal with Milk Fat Depression. Milk components are a major source of income on dairy farms around the world and when the amount of fat in milk decreases, so does the dairy’s income. To manage this, it is important to understand what milk fats are, how they are made and how to manage diets to maximise the potential of milk fat quantity and quality.
“You are what you eat”
Milk components are highly influenced by diet ingredients and composition. The main parts of a dairy cow’s diet are forage and concentrates (maize, grains and other feed ingredients). Forage is a great source of Triglycerides and the maize/concentrates can be a high source of Glycolipids.
Bugs in the rumen find it hard to break these down at first, as these molecules often are UNSATURATED (have double carbon bonds). These can be quite toxic to some rumen microbes. So they add Hydrogen atoms to the unsaturated bonds, thus saturating them (in a process called Biohydrogenation).
This process takes TIME, as the microbes add one Hydrogen atom at a time in a stepwise fashion. Fat molecules are in long chains (2 to up to >24 carbon atoms described as C18 – 18 carbon atoms and :3 which would be 3 unsaturated bonds) so the bugs tend to add atoms in patterns such as: C18:3 then C18:2 then C18:1 etc.
The importance of C18:1 trans10
One of the most POTENT inhibitors of milk fat is a lipid of 18 carbons long, with one unsaturated, trans bond at position 10 (C18:1 trans10). Even tiny amounts of this in the rumen can depress milk fat by over 20%. So managing milk fat depression is often about allowing sufficient TIME and the right POPULATIONS of bugs in the rumen to fully hydrogenate this milk fat to C18:0.
Managing Milk Fat Depression
Fibre in a dairy cow’s diet is extremely important for microbe health as well as decreasing food throughput times. So making sure that there is enough physically effective fibre in the feed is crucial to manage milk fats and decrease the risk of build-up of C18:1 trans10. Making SURE that you are using shaker boxes such as a 4-stage Penn State Sieve on feed-out and refusals will give a really good idea of how much chance cows have to SORT the food and how much fibre is getting into the rumen.