ANSC 307 - By-Products🥩🥓🍔

By-Products of the Meat Industry

Objectives

• To familiarize the student with the importance of by-products to the meat industry.

• To discuss the ultimate uses of edible and inedible by-products in the meat industry.

• To show the various uses of animal by-products for the pharmaceutical industry.

Importance of By-Products

• By-products in the livestock industry significantly contribute to the profitability of operating packing plants.

• It has been estimated that by-products provide approximately 10% of the overall value of livestock, though this can vary depending on the species being processed.

Live Weight to Carcass and By-Product Yields

• A chart outlines the relationship between live weight and various carcass components along with the by-product yields for different animals.

USDA By-Product Drop Value (Steer)

• The USDA drop values for by-products as of September 29, 2023, are detailed in the following table.

Take-home Message

• For each live animal, not all parts will be processed for consumption; the remainder typically converts into various by-products.

• Some by-products have specialized uses in culinary applications (such as particular styles of cuts) or in industries including bio-diesel production.

Examples of Edible Meat By-Products

• The following table lists various edible by-products along with their principal uses:

Examples of Inedible Meat By-Products

• The following table outlines various inedible by-products along with their principal uses:

Hides, Skins, and Pelts

• The classification of hides, skins, and pelts based on their origin and weight is as follows:

Effects of Brands

• The branding of hides affects their value:

  • Native (Unbranded): Most valuable.

  • Butt brand (Branded on rump area): Decrease value by -$3 per hide.

  • Colorado brand (Branded on side): Decrease value by -$6 per hide.

Pelts Classification

• Wool length classification illustrates value:

  • Wool pelts (most valuable): Greater than 1-1/2 inches.

  • Fall clips: 1 to 1-1/2 inches.

  • Shearlings 1: 1/2 to 1 inches.

  • Shearlings 2: 1/4 to 1/2 inches.

  • Shearlings 3: 1/8 to 1/4 inches.

  • Shearlings 4 (least valuable): Less than 1/8 inches; it is valuable since it hasn't been exposed.

  • A higher wool density on the animal translates to increased value.

Tallows and Greases

• Titer: Refers to the congealing or solidification point of the fatty acids in the fat.

• Tallow: Defined as fat having a titer above 40°C.

• Grease: Defined as fat having a titer below 40°C.

• Greases = higher titer; Tallow = lower titer

Dry Rendering Process

• In this process, fatty tissues are placed in a horizontal, steam-jacketed cylinder that possesses internal rotating blades.

  • Purpose: To rupture fat cells and release melted fat from supporting tissues.

• Once adequate moisture has been cooked out, the mixture undergoes filtration or straining to remove cracklings from the rendered tallow or grease.

Animal Feeds and Fertilizers

• Dried blood (blood meal): Derived from coagulating fresh blood with steam, removing the liquid, and drying the coagulum.

• Meat meal: Produced from proteinaceous materials obtained from the inedible rendering process.

• Steamed bone meal: Made by cooking bones with steam under high pressure to eliminate leftover fat and meat.

Gelatin and Glue

• Gelatin: Created from skins or hides, connective tissues, cartilage, and bones of cattle and calves.

  • Cooking these materials in water converts collagen into gelatin.

• Glue: Also sourced from the same items as gelatin but extracted by successive heating in water at specific temperature conditions.

Pharmaceuticals

• Various glands are utilized in extracting hormones and other compounds for pharmaceutical applications:

  • Adrenal glands: Epinephrine extracted from the adrenal medulla; adrenocortical extract from the cortex.

  • Ovaries: Source of estrogens and progesterone.

  • Pancreas: Yields insulin and trypsin.

  • Parathyroid glands: Produce parathyroid hormone, important for muscle function.

  • Pituitary gland: Source of ACTH (adrenocorticotropic hormone) essential for stress response.

  • Testes: Source of hyaluronidase.

  • Thyroid glands: Supply thyroxine and calcitonin, vital for metabolism regulation.

Tissues and Organs

• Various tissues and organs have significant uses in pharmaceutical products:

  • Blood: A source of albumin and essential amino acids.

  • Bone: Provides calcium and phosphorus.

  • Intestines: Employed in surgical sutures and condom production.

  • Liver: Supplies liver extracts and bile extract, useful for cortisone production.

  • Lungs: Source of heparin, used as an anticoagulant.

  • Spinal cord: Source of cholesterol, a precursor to Vitamin D.

  • Stomach: Rennet from calves, mucin from pigs, and pepsin from pigs are useful in digestive aid formulations.

Other By-Products

• Fetal calf blood: Utilized in cancer and AIDS research.

• Aorta valves: Used for replacement of defective human heart valves.

• Fetal pigs: Employed in biology teaching.

• Gall stones: Traditionally used as aphrodisiacs in the Far East.