Digestive Systems

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Digestive Systems
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Agriculture, Food, and Natural Resource Standards
Addressed

• AS.03.01. Analyze the nutritional needs of
  animals.
• AS.03.01.01.a. Identify and summarize essential
  nutrients required for animal health and analyze
  each nutrients role in growth and performance.
• AS.03.02 Analyze feed rations and assess if they
  meet the nutritional needs of animals.
• AS.03.02.01.c. Select appropriate feedstuffs for
  animals based on a variety of factors (e.g.,
  economics, digestive system and nutritional
  needs, etc.)

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The Ruminant Digestive System
Small intestine
Rectum
Rumen
Cecum
Esophagus
Reticulum
Omasum
Colon
Abomasum
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The Non-Ruminant Digestive System
Rectum
Colon
Stomach
Esophagus
Small intestine
Cecum
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The Cecal Fermenter Digestive System
Rectum
Small intestine
Esophagus
Stomach
Cecum
Colon
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The Digestive Process

• Mechanical digestion begins in the mouth where
  food is chewed and broken down into smaller
  pieces

Peristalsis a muscular contraction that causes
food to move through the digestive tract

• Chemical digestion enzymes and acids reduce
  food particle size and change particles into
  forms that can be used by the animal

Absorption nutrients are absorbed into the
blood stream through the intestinal villi
Metabolism nutrients are removed from the
bloodstream and used by the body organs for
things like bone and hair growth, maintaining
body temperature, etc.
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Major Nutrients Functions

• Protein- Development and repair of body organs
  and tissues. Production of wool, milk, eggs.
  Fetal development. Production of hormones and
  enzymes. Antibody development. Transmission of
  DNA.
• Carbohydrates- Support bodily functions such as
  breathing, digestion, and exercise. Help
  maintain body temperature. Store fat.
• Lipids- Enhance palatability and caloric value of
  feed. Provide energy. Provide fatty acids for
  healthy skin and coat. Aid in absorption of fat
  soluble vitamins. Help maintain body
  temperature. Provide essential materials for
  hormone secretion.

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Major Nutrients Functions cont.

• Water- Support biochemical reactions
  (respiration, digestion, conversion of food to
  absorbable components). Transport of nutrients.
  Help maintain body temperature. Helps give the
  body its form. Carries waste form the body.
• Vitamins- Regulate digestion, absorption,
  metabolism, gland activity, and cell formation.
  Necessary for normal vision. Fights diseases.
  Develop a healthy nervous system.
• Minerals- Furnish structural material for teeth
  and bones. Aid in building body tissue,
  digestion, muscle activity, and transmission of
  messages through the nervous system. Part of
  hormones.

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Marketing Concepts

• Nutritional value markets food based on
  specific nutritional content of the food.
• All purpose based on the concept that one food
  is adequate for all stages of the pets life.
• Price uses low price concept or more for
  your money. Price can be very misleading.
• Palatability markets based on how the food
  tastes to the pet

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Cost per Feeding Analysis

•       Determines cost per day and per year
•       Compares pet foods for economical value
  (which one gives you more for your money)
• The most economical pet food may be the more
  expensive one!

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What is Dry Matter

• Dry matter nutrient content of a food after all
  water has been removed
• When comparing a wet food to a dry food is
  necessary to first determine the dry matter
  content. This gives a more accurate nutritional
  comparison.
• Dry matter 100 - moisture
• I.e. A canned food with 70 moisture has 30 dry
  matter
• 100 - 70 30 dry matter

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Calculating MER Maintenance Energy Requirements

• MER Maintenance Energy Requirements
• MER is the amount of energy needed by an animal
  to keep it in good health. It varies with age,
  activity level, production, reproduction, and
  environmental conditions.
• MER is measured in kilocalories per day
  (Kcal/day)