Nicole Wagner

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Nicole Wagner
Animal Nutrition
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Table of Contents

• Nutritional Requirements
• Food Types
• Feeding Mechanisms
• Overview of Food Processing
• (Click on topics to access slides)

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Nutritional Requirements

• Animals are heterotrophs that require food for
  fuel, carbon skeletons, and essential nutrients.
• By definition a heterotroph is an organism that
  obtains organic food molecules by eating other
  organisms or their by-products.

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A nutritionally adequate diet satisfies three
needs

1. Fuel , chemical energy for the cellular work of
   the body.
2. Organic Raw Materials in the form of carbon
   skeletons used in biosynthesis
3. Essential Nutrients which are substances that the
   animal cannot make for itself from any raw
   material and must be obtained from food in a
   prefabricated form

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Food Types

• Animals fit into one of three dietary categories
• Herbivores, animals that eat mainly autotrophs
  (plant and algae)
• Carnivores, animals that eat other animals
• Omnivores, animals that regularly consume animals
  as well as plant or algal matter
• However, most animals are opportunistic feeders
  eating foods that are outside their main dietary
  category when these foods are available.
• (Click on highlighted words for links to web
  resources)

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Feeding Mechanisms

• Diverse feeding adaptations have evolved among
  animals.
• Four main groups of mechanisms by which animals
  ingest food
• Suspension-feeders many aquatic animals that
  sift small food particles from the water.
• Substrate-feeders (deposit-feeders) animals that
  live in or on their feed source, eating their way
  through the food
• Fluid-feeders animals that survive by sucking
  nutrient-rich fluids from a living host
• Bulk-feeders animals that eat relatively large
  pieces of food

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Overview of Food Processing

• The four stages of food processing
• Ingestion the act of eating
• Digestion enzymatic breakdown of the
  macromolecules of food into their monomers
• Absorption body cells take up nutrients such as
  amino acids and simple sugars from the digestive
  system
• Elimination occurs as undigested material passes
  out of the digestive system as feces