Nutritional Priorities of Cows
'Individual herds vary by breed, frame, or type (i.e., English or Continental) but their nutritional priorities are similar. When nutrient intake fulfills the highest priority requirements, the excess is used to fill lower priority requirements. When all current requirements are fulfilled, the excess is stored as fat.
Most English and Continental beef breeds tend to deposit excess fat externally (subcu-taneous), whereas dairy and Brahman-influenced breeds deposit more fat internally (KPH or mesenteric). During periods of low energy intake, excess external body fat is the first body tissue used to meet nutritional requirements. When energy is insufficient, fat stores may not be enough to fulfill requirements. When this happens, muscle (protein) is broken down to satisfy energy demand.
Cattle generally deposit external (subcutaneous) fat in the body in the following order: 1) back or loin, 2) ribs, 3) tailhead, 4) brisket, 5) flank, 6) vulva and/or rectum, 7) udder or mammary gland. When requirements exceed nutrient intake and external fat is broken down, it is utilized in the reverse order.'
Body Condition Scoring I: Managing Your Cow Herd Through Body Condition Scoring