Cattle - Raising Small Animals - page 430

you in feed costs compared to the daughters of other bulls. $EN is expressed in dollars sav-
ings per cow, so a higher value in this category is preferable.
• Carcass: Carcass measurements are an indication of the yield from the final beef product.
These include:
Carcass weight (CW) predicts the hot carcass weight of a bull's offspring compared to other
bulls. Hot carcass weight is a measure in pounds after an animal is slaughtered and its head,
organs, intestinal tract, and hide are removed, but before the carcass is chilled. Hot carcass
weight is usually about 60 to 65 percent of the animal's live weight.
Marbling (marb) is a fractional difference in USDA marbling scores. USDA assigns beef
grades based on the level of marbling, or fat within the muscles. The marbling EPD compares
the projected fractional difference in marbling scores from one bull's offspring to another's. It
is expressed as a percent of one-third of a marbling score. Higher marbling EPD scores are
usually desirable.
Fat thickness (FAT) is calculated as 60 percent from the measurement at the 12th rib and 40
percent of fat at the rump. It is used to predict the overall fatness of an animal. Individual
farmers will have to decide if they want this measurement to be higher or lower. Although fat
is an indication of tenderness, fat can reduce the percentage of edible meat from the animal.
Ribeye area (REA) is a square-inches prediction of ribeye area for a bull's offspring. The
ribeye area is where the most desirable steak cuts come from. The ideal ribeye area range is
12 to 14 inches, according to research from the University of Georgia that was published in
the Journal of Animal Science . Anything larger than this may be hard to sell.
• Ultrasound: Like the carcass scores, ultrasound scores predict the finished beef product.
Ultrasound scores, however, are based on the results of an ultrasound image so the data
comes from the live animal, rather than a carcass. Traits measured include:
Intramuscular fat (%IMF) predicts the difference in intramuscular fat in the ribeye muscle
compared to calves of other bulls.
Beef cattle are bred when they reach around 650 to 750 pounds or around the age of 14
months. A heifer must be well developed before breeding, or she may experience a difficult
delivery. Heifers should be fed carefully during pregnancy, as they still will be growing; you
do not want them to gain too much fat, because that can lead to pregnancy problems. The