Feeding Management and Digestion

Feeding Management

• Fundamental energy and metabolic substrates are classified as essential or nonessential.
• Raw materials used in food compounding are called ingredients.
• Formulas select and apportion ingredients for specific diets.
• The resulting nutrient profile shows the quantitative distribution of individual nutrients in the formula.
• Mechanical digestion includes chewing and peristaltic movement.
• Chemical digestion involves enzymes acting on fats, carbohydrates, and proteins.
• The digestive tract, from mouth to anus, breaks down food.
• The mouth starts food breakdown with chewing and saliva.
• Saliva lubricates and further breaks down food, responding to sight and smell.
• Saliva is composed of water, salt, mucus, and amylase.
• Teeth help break down food, while the tongue moves it around the mouth.
• Food passes through the esophagus and into the stomach's cardiac sphincter.
• The stomach acts as a reservoir for ingested food, beginning digestion.
• Digestion is aided by enzymes and peristaltic movements in cats and dogs.
• The pyloric sphincter regulates movement into the small intestine.
• The small intestine continues mechanical digestion through intestinal wall contractions.
• The small intestine has three parts: duodenum, jejunum, and ileum.
• Pancreatic and bile ducts enter the small intestine.
• Food moves through the ileocecocolic valve.
• The large intestine includes the cecum, ascending, transverse, descending colon, and rectum, and anus.
• The large intestine absorbs water and electrolytes, ferments food, and stores feces.
• Bacteria populations are important in the large intestine.

Digestibility

• Digestibility is the absorptive capability of a nutrient.
• A balanced diet provides all essential nutrients and energy.
• Higher digestibility reduces the animal's food consumption.
• Digestibility is determined by the amount of nutrients in food to the amount in feces.

Energy Balance

• Energy intake sufficient to meet the animal's needs and minimal change in stored energy.
• Energy storage changes occur during growth and pregnancy.
• Excess energy is stored as lean body tissue or fat.

Common Measurements

• BER (Basal Energy Requirement): Energy required for vital organ functions in a resting, awake, fasting state. Measuring it is impractical as stress caused by measurements increases metabolic rates.
• RER (Resting Energy Requirement): Energy use while resting in a thermoneutral environment, not fasted. This is easier to measure.

Other Energy Measurements

• Gross Energy (GE): Total energy content of a food source determined by burning it.
• Digestible Energy (DE): Energy left after digestion, removing fecal losses.
• Metabolized Energy (ME): Energy left after digestion, excretion of urine, and respiratory losses.
• Kilocalories (kcal): Unit of energy used to determine the temperature increase of a gram of water.
• Net Energy: Energy available to the animal for vital functions, growth, and reproduction.

Specific Energy Requirements (RER, MER, DER)

• MER (Maintenance Energy Requirement): Energy needed by a moderately active adult animal in a thermoneutral environment. Maintenance of existing energy levels and spontaneous activity.
• DER (Daily Energy Requirement): Average daily energy needs, considering activity level (work, lactation, pregnancy)

Gross Energy (GE)

• Amount of heat produced by burning a specific amount in a bomb calorimeter.
• Digestible energy (DE): Energy in a food that is left over after digestion.
• Metabolized energy (ME): Energy after losses. kcal (kilocalorie): Unit of energy used to determine the temperature increase of a gram of water.

Net Energy

• Available to the animal for vital functions, physical growth and repair
• Used primarily for maintenance and then for production (growth, reproduction).

Energy Expenditure

• Voluntary muscular activity and body heat production.
• Meal-induced thermogenesis and reproductive status.
• Environmental temperatures also influence energy expenditure, as well as thermoregulation.

Feeding Goals for Animals

• Enhancing quality of life, extending lifespan, slowing disease, eliminating or minimizing clinical signs of disease, and maintaining ideal body condition score (BCS)
• Naturally slowing metabolism with age.

Important Considerations in Geriatric Animals

• Cats and dogs have reduced Dietary Energy Requirements (DER) as they age.
• Gerontological conditions such as cancer, kidney disease, and heart disease may affect the energy needs of the animal.

Other Factors Influencing Feeding Requirements

• Body composition changes, lowered activity levels, and hormonal changes.
• Food composition differences in protein, fat and carbohydrates.
• Varying levels of activity influence the energy requirements.

Calculations for Energy Needs

• Energy needs are calculated by multiplying the RER by appropriate factors depending on intensity, length and frequency of work done.

Explore the principles of feeding management, including essential nutrients, ingredients, and formulas. Learn about mechanical and chemical digestion, saliva composition, and the functions of the mouth, esophagus, and stomach. Understand the initial stages of food breakdown and digestion.