ANIMAL NUTRITION

• Animals


  Must feed to obtain energy and acquire molecules they cannot produce
• Animals


  • Tube Worms
  • Whale Shark
  • Giraffe
  • Lion

  
• Animals


  • Have evolved various mechanisms to obtain food to sustain their nutritional requirements

  
• Mechanisms to obtain food


  • A crab feeding on algae
  • A plankton-feeding manta ray
  • A fruit-feeding bearded dragon
  • A carnivorous snake
• Nutritional requirements of animals


  • Locomotion
  • Growth
  • Respiration
  • Development
  • Nervous function
  • Circulation

  
• Carbohydrates


  Animals usually obtain carbohydrates from their plant-based diet
• Carbohydrates


  • Serve as the primary energy source in the cells of animals
  • Animals cannot produce their own carbohydrates, unlike plants
  • Cells use glucose as the primary carbohydrate that is oxidized during respiration
  • Carbohydrates also serve other functions such as in structural and signalling molecules
• Animals that obtain carbohydrates from plant-based diet


  • Termites
  • Goat
• Cellulose


  • A carbohydrate found in plant-based diet of various animals
  • Some animals cannot digest it due to the type of glycosidic linkages
  • Termites and ruminants have protozoa and bacteria in their gut that can digest cellulose
  • Humans cannot digest cellulose, but it is a component of our dietary fiber
• Animals that obtain proteins


  • Hyena feeding on flesh
  • Anteater feeding on ants
  • Egg predation by a snake
• Amino acids


  • Essential
  • Nonessential
• Proteins


  • Essential biomolecules needed for tissue growth and repair
  • Integral components of cytoplasm and membranes of cells and organelles
  • Digested to provide essential amino acids that animals cannot produce
  • Integral components of almost all of the enzymes in the animal body
• Animals that obtain lipids


  • Polar bear feeding on the carcass of a narwhal
  • An Adelie penguin regurgitating a krill
  • A squirrel feeding an a lipid-rich avocado
• Lipids


  • Essential nutrients that make up most of the membranes of cells
  • Essential in the synthesis of the myelin of nerve fibers
  • Important to the biosynthesis of various lipid-based hormones
  • Energy-storage molecules that can release more energy when oxidized
• Animals that obtain nucleic acids


  • Eagle feeding on a snake
  • Sea urchin feeding on algae
  • Panda feeding on bamboo
• Nucleic acids


  • Digested alongside ingested cells of other organisms
  • Digested into their constituent nucleotides for absorption by the body
  • Absorbed nucleic acid components are used to synthesize DNA, RNA, and ATP
  • For most animals, nucleic acids are not essential because they can be produced
• Animals that obtain vitamins and minerals


  • Crickets feeding on carrots
  • Caterpillar feeding on a leaf
  • A rabbit feeding on veggies
  • A snail feeding on a breadfruit
• Minerals


  Important elements that animals need to obtain from their diet, including phosphorus, sulfur, potassium, magnesium, and zinc
• Vitamins


  • Trace organic compounds present in the diet of animals
  • Essential vitamins in the diet of animals can either be water-soluble or fat-soluble
• Vitamins


  • Vitamin A
  • Vitamin B6
  • Vitamin B12
  • Vitamin C
  • Vitamin D
  • Vitamin E
  • Vitamin K
• Vitamin A


  Effective in the treatment of eye disorders and skin infections; needed for the growth of bones and tooth
• Vitamin B6


  A crucial component of an enzyme; needed for red blood cell production; thus it relieves anemia
• Vitamin B12


  Crucial enzyme component for cellular reproduction; improves nerve function
• Vitamin C


  Crucial enzyme component for protein metabolism; improves immunity; acts as an antioxidant
• Vitamin D


  Aids in the absorption of calcium in the digestive tract
• Vitamin E


  With antioxidative functions
• Vitamin K


  Reduces menstrual pain and internal bleeding; blood clotting
• Mechanisms of nutrient procurement in animals


  • Filter Feeding
  • Use of Tentacles
  • Suction Feeding
  • Use of Beaks
  • Jaws and Teeth

  
• Filter feeding


  Trapping food particles from drawn water, then moving them into the cell via bulk transport, and performing intracellular digestion via lysosomal enzymes
• Animals that use filter feeding


  • Sponges
  • Whales
• Whales' filter feeding


  They use their brush-like teeth called baleen to filter krills from marine water, engulfing water with dense krills and forcing the water out of their mouth
• Other animals that use filter feeding


  • Giant Clam
  • Anchovies
  • Whale Shark

  
• Use of tentacles


  The prey obtained through tentacles is moved into the gastrovascular chamber, where the gastrodermis tissue secretes enzymes to digest the prey's soft tissues, and undigested food particles are expelled through the mouth region
• Animals that use tentacles to obtain food


  • Hydra
  • Cephalopods (cuttlefish, squid, nautilus, octopus)
• Suction feeding


  Earthworms have a strong muscular pharynx that acts as a suction tube in the soil, pushing the moistened food materials into the crop for mechanical digestion in the gizzard
• Other animals that use suction feeding

  • Leeches
  • Insects (butterflies, flies, mosquitoes)
• Use of beaks

  The beaks of birds are structurally adapted to the type of their food, reflecting the birds' ecological and evolutionary history
• Use of jaws and teeth

  • Jaws and teeth are usually used by fishes, reptiles, and mammals to seize their prey
  • The morphology of the teeth reflects the diet type and evolutionary history of the animal
• Animals have basic biomolecule requirements to sustain biological functions
• Carbohydrates are important biomolecules needed by animals as a primary source of energy