Beef Grading and Classification

Beef Quality Grades

• Found in fine restaurants and gourmet stores
• Beef quality grades are determined by the amount of marbling and carcass conformation
• Prime grade has the most marbling and is not economical for the meat packer
• Choice grade is the most economical and desirable carcass grade
• Select grade has slight marbling and is not marked with a USDA stamp
• Standard grade has minimum marbling or below average carcass conformation
• Commercial grade is usually processed into lunch meats, soup, and canned meat products
• Cull grade is not acceptable for human consumption

Yield Grades

• Identify carcasses for differences in cutability (lean yield of a beef carcass)
• Yield grade is determined by hot carcass weight, external fat, percent heart, kidney, and pelvic fat, and rib eye area
• Types of yield grades:
  • Moderately Abundant
  • Slightly Abundant
  • Moderate
  • Small
  • Slight
• Yield grade 1 is the leanest, heaviest muscled carcass, and yield grade 5 is the lightest muscled, fattest

Dressing Percentage

• The percentage yield of chilled carcass in relation to the weight of the live animal
• Dressing percentage depends on the quality grade of the animal
• Example: a 1000 lb prime steer would produce a 620 lb carcass

Health

• Temperature: 100-102.5 degrees Fahrenheit (calves: 101-103)
• Heart rate: 60-70 beats per minute
• Respiratory rate: 8-16 breaths per minute

Nutrition

• Six basic nutrients: protein, carbohydrates, lipids, minerals, vitamins, and water
• Protein: provides essential amino acids, essential for growth and repair, forms part of muscles, internal organs, skin, hair, wool, feathers, hoofs, and horns
• Carbohydrates: used as energy, represent the largest part of an animal's feed supply, fibrous part of the diet, include sugars, starch, and cellulose
• Fats: concentrated source of energy, form cholesterol, steroids, and other body compounds, found in every cell, composed of carbon, oxygen, and hydrogen
• Minerals: needed in nearly all parts of the body, primarily found in bones and teeth, divided into macro and micro minerals
• Vitamins: required for health, development, and metabolic reactions, needed in small amounts, divided into fat-soluble and water-soluble vitamins
• Water: most important nutrient, accounts for 70% or more of the composition of most plants and animals, controls body temperature, enables living plants and animals to hold their shape, involved in transport of nutrients and waste, helps in digestion of feeds

Common Forages for Beef Cows

• Cool-season perennials: most growth occurs in spring and fall, include tall fescue, bluegrass, orchard grass, perennial ryegrass, clover, alfalfa, birdsfoot trefoil, and lespedeza
• Warm-season perennials: most growth occurs in summer, include bermudagrass, switchgrass, and flaccidgrass
• Winter annuals: must be planted each year, most growth occurs in early spring and late fall, include annual ryegrass, cereal grains, arrowleaf clover, and crimson clover
• Summer annuals: must be planted each year, most growth occurs in late spring and summer, include pearl millet, tifleaf millet, and sorghums

Digestive System

• Ruminant Defined: an animal with four distinct compartments in its stomach, which swallows its food essentially unchewed, regurgitates it, chews it thoroughly, and reswallows it
• Four Compartments of the Ruminant:
  • Reticulum (honeycomb)
  • Rumen (paunch)
  • Omasum (manyplies)
  • Abomasum (true stomach)