ADSC 2010 Lecture 10Outline of Last Lecture I. Meats – Proteins1. Myofibrillar Proteinsa. Myosin and Actinb. Troponin and Tropomyosin2. Stromal or Connective Tissue Proteinsa. Collagenb. Elastin II. Meat – LipidsA. Muscle FatIII. Meats – Nutritive IV. Meats – Acceptability1. Tenderness2. Juiciness3. Flavor & Aroma4. Appearance5. PriceV. Meat-Value DeterminantsA. Carcass WeightB. Carcass Category and Gradea. Beef1. Yield2. Quality Outline of Current Lecture: Meats- NutrientsI. NutrientsA. Six Classes of NutrientsII. WaterA. FunctionsB. Average Daily ConsumptionIII. CarbohydratesA. Classification of Carbohydratesa. Monosaccharaidesb. Disaccharidesc. PolysaccharidesB. Functions of CarbohydratesIV. Fats/LipidsA. ClassificationB. Types of Fatty AcidsC. Physical FormsD. Dietary Requirementsa. Essential Fatty Acidsb. Compounds Lipidsc. SterolsE. FunctionsV. ProteinsA. Amino AcidsB. Essential Amino AcidsC. Semi-Essential Amino AcidsD. Non-Essential Amino AcidsE. Dietary Crude ProteinF. Non-Protein Nitrogen (NPN)Current LectureI. Nutrients- The study of feedstuffs and their efficient utilization by livestock in producing animal products such as meat, milk, wool, and work- Feed costs are the Largest Production Costs in the livestock industry (60-75%)- Nutrient: a feed constituent (chemical substance) that is absorbed from the digestive tract and its metabolized by the body to support lifeA. Six Classes of Nutrients1. Water ***MOST IMPORTANT2. Carbohydrates3. Fats/Lipids4. Proteins5. Vitamins6. Minerals- Essential Nutrients: cannot be synthesized by the body and must be supplied through the dietII. Water- Comprises 70-75% of body weight- Most highly consumed Nutrient (>2:1)- Animals will die more quickly from lack of H2O than lack of any other nutrientA. Functions1. Transportation2. Media for Metabolic RXNS3. Thermoregulation4. Lubrication5. Gives cells their shape: osmotic pressureB. Average Daily ConsumptionSwine 1.5 – 3 Gal/DayCattle 10 – 14 Gal/DayHorses 10 – 14 Gal/DaySheep 1 – 3 Gal/DayIII. Carbohydrates- Provide energyA. Ways we measure energy content:1. Calories (Cal): heat required to raise the temperature of 1g of H2O 1°C from 14-15.2. KiloCalories (Kcal): 1000 calories3. MegaCalories (Mcal): 1 million calories- Energy content: ~4.2 Kcal/gramB. Classification of Carbohydratesa. Monosaccharaides: Simple sugars (5-6 carbons)1. Glucose (Glu): 6 Carbons- Dextrose2. Fructose (Fru): 6 Carbons3. Galactose (Gal): 6 Carbons4. Ribose/Deoxyribose: 5 Carbonsb. Disaccharides 1. Sucrose (Glu + Fru): α (alpha) 1-2 Linkage2. Lactose (Glu + Gal): β (Beta) 1-4 Linkage3. Maltose (Glu + Glu): α (alpha) 1-4 Linkagec. Polysaccharides (C5H10O5)1. Starch (GLU) - α 1-4 Linkage- Used primarily for energy storage in plants- Primarily in “concentrates”***Concentrates: high energy, low fiber feedstuff that is highly digestibleExamples: corn, grain sorghum, wheat2. Glycogen Animal Starch- Stored in liver and muscle3. Cellulose (GLU) - Β 1-4 Linkages- Located in the cell walls of plants- Lowly digestible- Primarily in “roughages”***Roughages: high fiber, low energy foodstuff that is lowly digestibleExamples: Hay, pasture silage4. Hemi-Cellulose: α & β 1-4 Linkage5. Lignin- INDIGESTIBLE!!!**Ruminants can break down Beta Linkages and StarchC. Functions of Carbohydrates1. Energy Source- 4.2 Kcal/gram- 50-75% Dry Matter = Carbs2. Fiber Content- Laxative Effect- Maintains healthy lining and muscle tone of digestive tract****Cellulose, heme-cellulose, and lignin****IV. Fats/Lipids: like carbs with lower proportion of elemental oxygenA. Classification- Simple Lipids = Triglycerides- Glycerol + 3 Fatty Acids  Triglycerides + 3H2OB. Types of Fatty Acids1. Steric Acids: Saturated, Linear2. Oleic Acid: Unsaturated- Have at least two carbon double bondsC. Physical Forms1. Solids (Fats): Saturated, long chains2. Liquids (Oils): Unsaturated, Angled chains- Dietary lipids can impact the physical characteristics of carcass fat, especially in “monogastrics”**Monogastrics: have one stomach usual with an acid environment Example: PIGSD. Dietary Requirementsa. Essential Fatty Acids1. Linoleic Acid (18:2)2. Linolenic Acid (18:3)3. Arachidonic Acid (20:4)b. Compounds Lipids1. Glyco-Lipids: Brain/nervous system2. Lipo-Proteins: Lipid transportation in body3. Phospho-Lipids: Important to cell structure c. Sterols1. Cholesterol: involved in membrane structure and a pre cursor forother compounds2. Steroid Hormonesi. Testosteroneii. Estrogen3. Vitamin-Pre-Cursors: ergosterol + sunlight  vitamin DE. Functions1. Storage form of metabolic fuel- 9.45 Kcal/gram 2.25X CHO- X= kilocal.2. Transportation of energy3. Aids in absorption of Vitamins4. Protection and Insulation of Vital organs5. Hormone Precursors6. Juciness and Flavor in Meats- Feedstuffs generally contain 1-4% Fats/lipids, except for oilseeds with contain more than 18%Examples: soybeans, cottonseed, canolaV. Proteins: Building blocks for animal proteinsA. Amino Acids: Basic Unit for ProteinsClasses of Amino Acids: B. Essential Amino Acids: MATT HILL VP- Methionine- Arginine- Threonine- Tryptophan- Histidine- Isoleucine- Leucine- Lysine- Valine- PhenylalanineC. Semi-Essential Amino Acids- Glycine- Tryosine- CysteineD. Non-Essential Amino Acids- Alanine- Aspartic acid- Glutamine- Glutamic acid- Serine- Asparagine- Proline***Chains of amino acids linked by “peptide bonds”- Condensation RXNE. Functions of Proteins1. Structure: Muscle, hair, feathers, cell wall- 70-80% of dry, fat-free body is protein!2. Regulation and Protection:- Enzymes- Antibodies- Hormones- Hemoglobin3. Energy= ~4 Kcal/grams**Protein Quality = determined by the ability of animals to digest and utilize the proteinF. Dietary Crude Protein- Crude protein of feedstuff is calculated on nitrogen content- Protein= ~16% Nitrogen (100/16=6.25)- % crude proteins = % X 6.25- Feedstuff with 4% Nitrogen equates 25% crude proteins- 4% N x 6.25 = 25% crude proteinsG. Non-Protein Nitrogen (NPN)- Example: urea, uric acids- Urea = ~45% nitrogen = 281.25 CP- Chicken Litter: ~35% CP***Mammals cannot use this form of Nitrogen, microorganisms in the Rumen can- Excess urea = TOXIC!!- <1/3 of dietary nitrogen from urea- <1% of total