AN SC 260 Ch.2

Chemical and physical breakdown of foods into smaller and simpler particles 

passage of molecules from the gi tract through the mucosal cells in to blood or lymph systems. 

• - assimilation of nutrients
• - exclusion of unnecessary or harmful substances (not everything we consume is good for us) 
• - some nutrients can be digested but not absorped. 

• - All have common elements, principals and processes of digestive physiology. All animals have similiar processes. 
• - All intake of food through the mouth, digestion of feed, absorption of nutrients, transport of absorbed nutritents to the site of metabolism, excretion of waste products, ultimate goal is maitenace. 

proteins - polypeptide to peptides and amino acids. Animal will use amimo acids to create protieins 

starches- sugars absorped and used for energy

structural carbohydrates (fibers) - 

triglyerides - fatty acids, mono and digylcerols. Broken down by the enzyme lipase.

• - Mono and diglyerides (lipids)
• - sugars (starches and structural CHO)
• -peptides and amino acids (proteins) 
• -vitamins, minerals, and water

Maitenance 

support growth, reproduction, movement, depostion of stored nutrients (reserves) 

eating - specialized mouth structures. type of teeth (grinding cutting), presence/absence of teeth.

digestive tract. diet is based on digestive physiology. Structures, functions from the start of the digestive tract to the end. 

absorption of nutrients. - transports and other mechanisms

metabolism of nutrients. - maintenace, production/work.

excretion of waste products. 

• - Feeces, typically stuff not used by the animal
• - Urine, excetion of excess nitrogen. 
• Ureotelic (urea, mammals), is the inbewteen. takes a fair bit of energy and water.
• Uricotelic (uric acid), birds and land reptiles. Doesnt take very much water but does take lots of energy to go to uric acid
• Ammonotelic (ammonia), fish. Needs lots of water (is very toxic) depends on how much water, can be acid. 

• -Monogastric (chicken)
• - Non ruminant (or monogastic) herbivorie (have very high diets and fibre)
• - Ruminant (have specialized able to use fibre effeciently, cows)

• Herbivore plants (sheep, deer)
• Carnivoire (moslty meat, bobcat)
• Omnivorie (meat/plants, humans and pigs have GI tract for both meats and plants)

No can be somewhat blurry

• - Pig, fowl, dog, mink, fish and monkeys.
• - Simplest digestive system
• -limited capacity (volume to body size)
• - limited/variable microbial action
• -limited fibre digestion
• -adapted to highly digestable diets (grains, digestible plant material) 
• see pic 3 lecture

• -horse, rabbit, guinea pig, hamster
• -feeding requirements bewteen monogastric and ruminant. 
• -functional ceccum. 
• -large intestine plus ceccum conatin microbes (fibre digestion produces VFA's leads to energy, microbes also lead to vitamin B synthesis)
• -fermentation occurs after much of the absorptive sections of the GI tract

Horses provide a good enviro for microbes to survive and ferment. Known as hind gut fermenters. Thats why they can eat hay and such. 

• -cattle, sheep, bison, deer, and elk
• -mouth, no upper incisor or canine teeth
• -four stomach compartments (rumen where most of the fermentation happens, reticulum, omasum, abomasum)
• -more space greater volume. 9x digestive capacity of the human

• Bacteria - 25-80 billion
• protozoa - 200,000 - 5,000,000 /ml

allows digestion of fibre - production of VFAs, also able to produce vitamin B's and essential amino acids

Symbiotic relationship. 

fermentation takes place before absorptive surfces 

humans have 10:1. shows that we are omnivoires. Shows that we eat meat which is quite easy to break down/absorb. Compared to cattle 20:1 have a large intestinal because it is harder to break down plants

• Ostrich 1:13
• Rhea 1:8
• Chicken 1:4
• Emu 1:4
• Cassowary 1:3

birds neeed to have effiecient DT. They have reverse parstalosis so are able to move food back and forth over the DT