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Chapter 12. Small Animal Nutrition. Learning Objectives. List the energy-producing and non-energy-producing components of food List the classes of carbohydrates and describe the catabolism of carbohydrates
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Chapter 12 Small Animal Nutrition
Learning Objectives List the energy-producing and non-energy-producing components of food List the classes of carbohydrates and describe the catabolism of carbohydrates Differentiate between lipids and fats and describe the general structure of triglycerides Describe the structure and functions of proteins
Learning Objectives Differentiate between essential and nonessential amino acids Explain the importance of water in metabolic reactions Differentiate between microminerals and macrominerals and give examples of each List the fat- and water-soluble vitamins and explain the importance of vitamins in metabolism
Learning Objectives Define the following terms: nutrient, ingredient, formula, nutrient profile, calorie, and kilocalorie Differentiate between dry, semimoist, and moist food and describe the characteristics of each Describe considerations in evaluating home-prepared diets
Learning Objectives List the legal requirements of pet food labels and considerations in evaluating pet food label information Describe the components of a nutritional assessment for dogs and cats List special considerations in feeding adult, pediatric, geriatric, pregnant, lactating, injured, and ill dogs and cats List and describe routes and procedures for providing nutritional support to hospitalized patients
Nutrient Terms Nutrient Energy and metabolic substrate classified as essential or nonessential Ingredient Raw material used in food compounding Formula Ingredient portions for a particular diet type Nutrient profile Quantitative distribution of individual nutrients within finished formula
Nutrient Terms Nutritional value Cannot be identified solely on an ingredient statement Analysis of a particular food Can only give an indication of nutrient content and availability of a particular nutrient Nutritional value Based on the absorptive capability of a nutrient Based on availability Digestibility of a food A measure of biological availability
Balanced Diet Supplies all key nutrients Supplies energy needed to meet daily requirements of the animal at its particular stage of life
Food Digestibility Digestibility Determined by a mathematical equation Compares amount of a nutrient in the food and amount of the same nutrient in the feces
Above-Average Digestibility Foods higher in fiber will be lower in digestibility Protein greater or equal to 85% Fat greater or equal to 90% Carbohydrate greater or equal to 90% Energy greater or equal to 85%
Palatability • Involves sensory factors such as: • Taste • Smell • Color
Additives Non-energy substances Non-nutrient substances Purposely added to foods to enhance: Color Flavor Texture Stability
Protection Against Microbes Physical and chemical means Dehydration (dry food) Heat (moist and dry food) Chemical treatments Preservatives (semi-moist and some dry food)
Humectants Preservative additives Bind to water Inhibit mold and fungal growth
Antioxidants Chemical agents Protect fatty acids and fat-soluble vitamins from becoming rancid By inhibiting oxidation Vitamins C and E
Energy-Producing Nutrients Carbohydrates Broken down into simple sugars Fats Broken down into triglycerides Proteins Broken down into amino acids
Energy Gained From Food Used to maintain and repair cell structures Higher degree of cellular activity = higher energy (nutritional) demands Growth Reproduction Exercising Healing from injury Combating a disease
Cellular Activity Requires Energy Oxygen synthesis Oxygen transport Heat production Muscle contraction New tissue synthesis
Carbohydrates Provide body with energy Excess stored as glycogen or converted to fat Include: Sugars Starches Fibers
Sugars Monosaccharides (simple sugars) Disaccharides (complicated sugars) Multiple sugars Broken down to provide energy stored in form of ATP
Starches Formed after complex digestion process Involves complex microbes and enzymes Salivary glands cannot always initiate digestion Food mixed with hydrochloric acids and enzymes in stomach Primarily digestion and absorption in small intestine Example is glycogen Animal-specific starch Provides rapid supply of glucose Stored in liver and skeletal muscle tissue
Insoluble Fibers Referred to as complex carbohydrates Examples Cellulose, lignin Sources Corn, wheat, rice, barley, oats, potatoes
Fiber Major energy source for grazing animals Digested by bacteria and protozoan microbes in large intestine of rumen, cecum, and large intestine Results of fiber digestion Short-chain fatty acids Acids then transformed into glucose Role of fiber in diet Depends of physiology of animal’s digestive tract
Role of Fiber in Companion Animals Increases bulk and water content of intestine Reduces caloric density for weight-control food while maintaining satiety Stabilizes blood sugar levels by extending time the nutrients are absorbed (diabetes mellitus) Assists in regulating bowel function
Breakdown Products from Fiber Maintain normal colonic function Decrease pathogenic intestinal bacteria Help in preventing intestinal cancer
Fats Serve as primary sources of energy Supply essential fatty acids Facilitate digestion Act as carriers for fat-soluble vitamins (A, D, E, K) Provide palatability and texture to food
What Is a Lipid? Fat—if solid at room temperature Oil—if liquid at room temperature Dietary fat Composed of units called triglycerides One to three fatty acids Held together by one molecule of glycerol Highly digestible Twice the caloric density of similar quantity of protein or carbohydrate
What Is a Fatty Acid? Saturated No double bonds in primary hydrocarbon chain Monounsaturated Fatty acid with one double bond Polyunsaturated Fatty acid with more than one double bond
Essential Fatty Acids Polyunsaturated and long-chain Necessary for body function Cannot be synthesized by mammals Must be obtained from food Known essential fatty acids Linoleic, α-linoleic, and arachidonic (cats) Linoleic, α-linoleic (dogs)
Functions of Essential Fatty Acids Integral part of kidney and reproductive function Key component to cell membrane formation Key component of prostaglandin production
Deficiencies of Essential Fatty Acids Alopecia Dull hair coat Anemia Hepatic lipidosis Essential fatty acid deficiency in the critical patient Increases susceptibility to infection Weakens cutaneous capillaries Promotes poor wound healing
Amino Acids Defined as any organic compound containing amino and carboxyl group Occur naturally in plant and animal tissue Chief constituents of protein
Protein Structure Long chains of amino acids held together by peptide bonds Roughly 22 known amino acid groups Arranged in countless number of ways, each having unique properties and characteristics Considered building blocks for plant and animal protein
Proteins Principal structural component of all body organs and tissues Serve as enzymes, hormones, and antibodies Essential to all living cells Functions Regulation of metabolism Construction of cell membranes Formation of muscle fiber Growth and repair of tissue
Amino Acids Nonessential Can be synthesized from other sources Essential Cannot be synthesized in the body in adequate quantities Must be supplemented in diet
Taurine Essential amino acid in cats Deficiency results Retinal degeneration Reproduction insufficiency Impaired immune system Dilated cardiomyopathy Deficiency signs Occur after prolonged periods of depletion Owners typically report visual changes or poor depth perception (“miscalculating” jumps)
Biological Value of Protein All proteins are not of equal worth Proportion utilized for growth and maintenance of normal body systems is measure of its biological value Animal proteins vs. plant-based proteins
Dietary Protein Protein is added to most commercial pet foods Correct balance of amino acid composition necessary to classify protein high in biological value Greater the protein quality, the less is needed Digestibility is an important factor
Commercial Pet Food Often a mix of animal and plant substances Provides multiple protein sources Improves overall quality of food by providing wide amino acid profile High-quality protein needed for periods of Growth Physical exertion Pregnancy and lactation Repair of damaged tissues
Protein Deficiency Amino acids not stored in body What happens if amino acids aren’t consumed? Breakdown of protein in viscera Breakdown of protein in skeletal muscle Gluconeogenesis
Gluconeogenesis Initiated by liver and kidneys using glycerol, lactate, and glucogenic amino acids Prolonged starvation in normal animals Signs of protein deficiency
Cats Specifically adapted to high-protein, low-carbohydrate diets Rely on gluconeogenic amino acids as a major source of energy Continuous protein catabolism
Catabolism Chronic anorexia, or starvation Can be reversed “Refeeding syndrome” Metabolic complications if food is consumed or administered too rapidly Clinical signs Cardiac arrhythmias Muscle weakness Hemolytic anemia Respiratory failure
Excess Dietary Proteins Converted to fat and stored as adipose tissue Although cats must consume twice the protein as dogs, feeding a food with proper levels of protein is essential Metabolism of excess amino acids increases liver and kidney workload
Protein Requirements Consumed every day to replace amino acids lost to catabolism Quality of protein is limiting factor Amino acids for protein synthesis
The Nutrient Water Does not produce energy Most important nutrient Functions: Essential for almost every chemical reaction Transports solutes and gases Regulates temperature Lubricates joints and eyes Balances electrolytes
Minerals Inorganic chemicals Important part of a balanced diet More than 18 mineral elements are essential for mammals Macrominerals Microminerals