ANSC 307 Exam # 2 Study Guide Lectures: 7 - 15Lecture 7 (October 6) By- Products of the Meat Industry - Contribution of by-products to the value of livestock would be 10%- Gustavus Swift transformed the whole by- product industry of meat carcasses- Understand that a 1,000lb carcass does not produce 1,000lb of meat- Steers followed by hogs and then lambs have the heaviest by-products- The value of hide has the greatest impact of hide and offal value (leather); today the valueof the hide is $12.38 or more than $16- Almost all of the edible by-products are exported; if steers are >30 months, there is a fear of BSE; - Hides drive the hide and offal value; economy drives the hide - Variety meats and blood have the lowest by- product yield; Inedible fats, bone, meat scraps and unaccounted items such as stomach have the highest by- product yield in relation to the live weight ****Know edible and inedible meat by-product uses on pages 33 and 34Hides and Skins- Unborn calf: slunk skin- Calf: Light skin calf, Heavy skin calf, Kip skin, Overweight kip skin- Cow: Light cow hide, heavy cow hide- Steer: extra light steer hide, light steer hide, heavy steer hide- Bull: 60 to 120lbs---- thickest hide - Stag: accepted as steer or bull depending upon characteristicsEffects of brands- Native- unbranded, most valuable; ex: Holstein- Butt brand- branded on rump area, $5/cwt discount- Colorado brand- branded on side, $10/cwt discount--- greatest discount Pelts- longest wool/ fleece length, the more valuable - Shearling 1- Shearling 2 - Shearling 3- Shearling 4 (least valuable) - Fall clips - Wool pelt (most valuable)Tallows and Greases - Titer — congealing or solidification point of the fatty acids in the fat. - Tallow — fat having a titer above 40°C. - Grease — fat having a titer below 40°C. - Dry rendering process — fatty tissues are placed in horizontal, steam-jacketed cylinders equipped with sets of internal rotating blades. Fat cells are ruptured, and the melted fat is released from the supporting tissues. When sufficient moisture has cooked out, the mixture is filtered or strained to remove the cracklings from the rendered tallow or grease; separates tallow or grease from cracklings Animal Feeds and Fertilizers - Dried blood (blood meal) — made by coagulating fresh blood with steam, draining off the liquid, and drying the coagulum; high in nitrogen - Meat meal- made from the proteinaceous materials from the inedible rendering process. - Steamed bone meal — made by cooking bones with steam, under a high pressure, in order to remove any fat and meat that may be left on themGelatin and Glue - Gelatin — made from skins or hides, connective tissues, cartilage, and bones of cattle and calves. Cooking in water converts the collagen in these materials to gelatin; high in collagen- Glue — made from the same items as gelatin, but is extracted from these materials by successive heating in water under specific temperature conditions.Pharmaceuticals Glands - Adrenal — epinephrine is extracted from the adrenal medulla and adrinocortical extract from the adrenal cortex. - Ovaries — used as a source of estrogen and progesterone (birth control) - Pancreas — yields insulin and trypsin (breaks down proteins)- Parathyroid-parathyroid hormone extract is used to prevent large scale muscular rigidity. - Pituitary — source of ACTH (adrenocorticotropic hormone). - Testes — source of hyaluronidase.- Thyroid — source of thyroxine and calcitonin (reduce bone loss)Tissues and Organs - Blood- source of albumin and amino acids. - Bone — source of calcium and phosphorous- Intestines — surgical sutures and condoms. - Liver — liver extracts and bile extract, which can be used to make cortisone. - Lungs — heparin (prevents blood clots) - Spinal cord — source of cholesterol, which is used to manufacture vitamins- Stomach — rennet (from calves), mucin (from pigs), and pepsin (from pigs).Other by-products - Fetal calf blood — used for cancer and AIDS research. - Aorta valves — for replacement of defective human heart valves. - Fetal pigs — used for biology teaching.- Gall stones — sold as aphrodisiacs in the Far East; “packer gold”Lecture 8 (October 8) Carcass Components and Muscle Structure Meat= edible portions of domestic mammals used for foodSpecies <3months 3-9months 1-2yrs >2yrsBovine Veal Calf BeefOvine Hothouse lamb Lamb Yearling mutton MuttonPorcine Slaughter pig Butcher hog Packer Sow, Stag, or BoarCaprine Cabrito Kid Yearling AdultEquine ---------------------------------Horse Meat-----------------------------------------Kinds of meat - Carcass: eviscerated body of domestic mammals. -Major — bone, connective tissue, muscle, fat. -Minor — skin, arteries, nerves, veins. - Variety meat: edible organs and glands. Kidney, liver, heart, brain, tongue, sweetbread (thymus gland), stomach, tripe, etc. - Reclaimed meat: products obtained from bone, fat or blood. Mechanically separated beef and pork — from hone; Lean finely textured beef— from fat; Plasma protein isolate — from blood- Processed meat: Frankfurters — made of 1, 2 and(or) 3 kinds of meat (carcass and variety meats) plus seasoning and cure ingredients; Hams — 1(carcass meat) plus cure ingredientsCarcass meat: Comprised of bone, connective tissue, muscle and fatFunction in living animal: - Bone: Protects organs, levers for locomotion, Support and rigidity - Connective tissue: Part of skeleton, Connects muscle to bones, Harness, collects activity ofmuscle fibers - Muscle: Produces energy- ATP, Converts energy to work - Fat: Storage of reserve energy, Insulation, Protects vital organs Muscle structure Muscle — a contractile organ comprised of connective tissue, muscle fibers and intramuscular fat; made up of muscle bundles which are made up of muscle fibersConnective tissue - Epimvsium — surrounds entire muscle - Perimysium surrounds muscle bundle - Endomysium —surrounds muscle fiber - Fibrils of stromal proteins: Collagen, Elastin and Reticulin - Dispersed in a watery matrix called ground substance Intramuscular fat (marbling) Deposits of fat in perimysium and endomysium Muscle fiber — muscle cell, the smallest completely functional unit in the muscle. 10 to 100 micrometers in diameter, 10 to 40 mm in length, striated appearance; made up of myofibrils which are made up of sarcromeresSarcomere- smallest, basic contractile unit-