Latitude and altitude —
hidden factors that influence omega-3 and CLA levels in milk
The amount of beneficial CLA and omega-3 fatty acids
in a cow's milk is influenced by a host of factors in addition to diet,
including her breed, individual genetics, age, and even the time of year.
Now one more factor has been added to the list: prevailing temperatures.
Milk and cheese from alpine grazers or cows raised in colder climates
appear to have the omega-3 and CLA edge.
The reason? It has to do with plant antifreeze. Omega-3
fatty acids stay fluid at colder temperatures than other, more saturated
fats. A plant that has to withstand the cold needs more of this natural
antifreeze to keep its cell membranes fluid. Cows that graze on this
cold climate grass ingest more omega-3s, which they then convert to another
good fat—CLA. In a recent study, cows that grazed in alpine meadows
had more than twice the amount of CLA in their milk as similar cows that
grazed down in the valley.
"Composition of milk fat
and correlation with fodder plants" Marius Collomb, Jacques-Olivier
Ueli Bütikofer, Robert Sieber, Hans Eyer,