Marbling is the fine flecks of fat that appear within the muscles of beef and lamb (also referred to as intramuscular fat). It is deposited unevenly throughout the body and is most present in the forequarter cuts.
Marbling is the last fat to be deposited and hence is the first fat to be used by the animal as an energy store. To maximise the marbling in beef, cattle must be on a highly nutritious diet – whether that be grass or grain. Different types of farming methods produce varying results.
Marbling can also be affected by genetics e.g. breeds such as Wagyu marble extensively.
Marbling has a positive effect on eating quality, and it is this marbling that contributes to the juiciness and flavour of beef and lamb. Marble scores are based on the amount and distribution of marbling through the eye muscle that makes up a striploin. In Australia marble scores are measured from 0 - 9+.