DIGESTIVE SYSTEM

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DIGESTIVE SYSTEM ABSORPTION OF FOOD NUTRIENTS

• AGRICULTURE PRODUCTION
• OCTOBER 2006
• MR. JANISCH

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INTRODUCTION

• DIGESTION--PROCESS OF BREAKING FEED DOWN INTO
  SIMPLE SUBSTANCE THAT CAN BE ABSORBED BY THE BODY
• ABSORPTION--TAKING IN THE DIGESTIVE PARTS OF THE
  FEED INTO THE BLOODSTREAM.
• RUMINANTSANIMALS THAT HAVE A STOMACH, DIVIDED
  INTO SEVERAL PARTS. CATTLE, SHEEP AND GOATS. CUD
  CHEWING
• NONRUMINANTSSIMPLE ONE COMPARTMENT STOMACHPIGS,
  HORSES, CHICKENS

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Digestive Systems

• Digestive Systemconsists of the parts of he body
  involved in chewing and digesting feed, moving
  the feed through the body and absorbs the
  products of digestion.
• Large differences between ruminants and
  nonruminants

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Difference

• Ruminants can digest large quantities of fibrous
  feeds hay pastures
• Nonruminantsneed high energy, low fiber ration
• ConcentratesGrains and protein supplement
• Roughagehigh fiber feeds hay, pasture
• Horsesdigest 39 of the roughage
• Swinedigest 22 percent roughage
• Bacteriadigest roughage in ruminants
• Produce proteins, B-Complex vitamins and Vitamin K

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PARTS OF DIGESTIVE SYSTEM

• Mouthfood enter the animal body.
• Esophagus/gullettubelike passage from the mouth
  to the stomach.
• Stomach receives the feed and add chemicals which
  help in the digestive process
• Small intestinelong folded tube attached to the
  lower end of the stomach.
• Large intestineLarger in diameter, but shorter
  in length
• Rectumend of the large intestine
• Anusfeces is passed through the anus

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Accessory Organs

• Mouthteeth, tongue, salivary glands
• Liverlargest gland in the body. Located along
  the small intestine just past the stomach.
• Bile--The thin, yellowish-brown or greenish
  liquid secreted by the liver
• Pancreasupper part of the small intestine.
• Pancreatic juice--The clear, watery fluid with an
  alkaline reaction secreted by the pancreas that
  aids in feed breakdown

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Poultry Difference

• Have no teeth
• Crop and gizzard
• Caceaattach to the small intestine
• Cloacaenlarge part connected to the large
  intestine
• Ventelimination of feces

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DIGESTIVE PROCESS

• Mouth Esophagus
• Chewing action of the mouth and teethbreaks up,
  cuts and tear up the feed
• Increase surface area of the feed particleshelps
  with chewing and swallowing process
• Salivastimulates the taste
• Enzymessubstance that are organic catalysts
  which speed up digestive process.
• Salivary amylase changes starch to maltose or
  malt sugar. Salivary maltase changes maltose to
  glucose.

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Ruminants Digestive

• Ruminant do not chew their food. Roughage are
  rechewed later.
• Ruminant (chewing the cud)
• Roughages forms ball-like masses in the stomach.
  
• The material is forced back up the esophagus to
  be chewed again.

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General Process

• Tongue direct the feed to the throat for
  swallowing.
• Chewed material enters the esophagus
• Food is carried down the esophagus by a series of
  muscle contractions
• Cardiavalve at the end of the esophagus
• Prevents food from coming back into the esophagus.

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Ruminant Stomach

• 4 PartsRumen, reticulum, omasum and abomasum
  HOLD 250 QUARTS OF FEED
• Ruminants eat rapidly
• Do not chew much of the feed before swallowing it
• Solid feed goes to rumen
• Liquidabomasum
• Rumen the feed is mixed and partially broken down
  by bacteria
• Slow churning and mixing takes place.

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Ruminant Stomach II

• Rumen is full, animal lies down
• Ruminationfeed is forced back into the mouth
• Cattle chew their cud about 6-8 x/ day.
• 5-7 hours is spent in rumination.
• Rumen and reticulum85 of the stomach
• Left side and middle of the animal.
• ReticulumKnown as the honeycomb and or hardware
  pouch.

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Bacteria and Protozoa

• Found in the rumen and reticulum
• Muscles break the food into smaller particles for
  the bacteria to act in the digestion process.
• Bacteria changes low quality protein into amino
  acids.
• Amino Acidessential for growth and maintenance
  of cells.
• As the bacteria diesanimals digest them for
  protein and vitamins.

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Bacteria and ProtozoaItems that affect them

• Type of feed
• Going from forage to concentratesbuilds up
  acids.
• pH5.5 to 8 (optimum is 6.5)outside of this
  rangereduces bacteria
• Ureais fed to the animals to increase ammonia,
  basic source of energy. Careful to make sure you
  do not burn the animals.

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Bloat

• Large amount of carbon dioxide and methane gas is
  released by the bacteria
• Disposed through the digestive system
• Excessive gas builds upbloat
• Fresh grass or legumes
• Gas Bloat
• Foamy Bloat.

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Omasum

• Makes up the 8 of the stomach
• Strong muscles in its wall
• MANY PLIES
• Function not really known.
• Squeeze water out of feed.

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Abomasum

• True Stomach
• Makes up 7 of the stomach
• Feed is mixed with gastric juice
• Grain goes straight to the abomasum.
• Same as in nonruminant animals.

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Rumen Development

• Abomasum is the only part of young ruminant
  animals developed.
• Young animals can not eat roughages
• Milk goes right to the abomasum.
• Rumen develops in two month along with the
  reticulum and the omasum
• 3 month of agerumen can begin its function

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RUMEN--MAIN COMPARTMENT CONTAINS BACTERIA TO
BREAKDOWN FOOD
RETICULUM-HONEYCOMB,HARDWARE
ABOMASUM-TRUE STOMACH
OMASUM--MANY PLIES-WATER
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SIMPLE STOMACHS

• SWINE
• HOLDS 8 1/2 QUARTS--TAKES 24 HOURS TO PASS
  THROUGH
• HORSE RABBITS SIMILAR
• HORSES CECUM COLON ENLARGE TO HOLD 120-140
  QUARTS OF FEED--
• CAN DIGEST LARGE AMOUNT OF ROUGHAGE--BACTERIA
  PRESENT IN AREA, AIDS IN DIGESTION OF ROUGHAGE

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NonRuminant Stomach

• Feed entersgastric juice begins to flow
• Juices come from glands in the wall of the
  stomach
• .2 to .5 hydrochloric acid
• Stops amylase
• Contains enzymespepsin, rennin and gastric
  lipase
• Muscular walls of the stomach churn and squeeze
  the feed.
• Liquids are pushed into the small intestine
• Gastric juice acts on the solids

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Gastric Juice

• Pepsinbreak down protein into proteose and
  peptones
• Rennincurdles the casein
• Gastric lipasesplits the emulsified fats into
  glycerol and fatty acids

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Small Intestine

• When feed leaves the stomachit is an acid, semi
  fluid gray, pulpy massChyme
• Chyme in small intestine, is mixed with three
  digestive juices Pancreatic juice, bile and
  intestinal juice.

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JUICES ENZYMES

• PANCREATIC JUICE--SECRETED BY THE PANCREAS
• TRYPSIN--BREAKS DOWN PROTEINS
• Proteose and peptones are broken down by trypsin
  and peptides
• Proteoses, peptones and peptides are amino acids
• Proteoses most complex and peptides the simplest.
• PANCREATIC AMYLASE--CHANGES STARCH IN THE FEED
  INTO MALTOSE. MALTASE--CHANGES SUGAR INTO GLUCOSE

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JUICES ENZYMES II

• LIPASE--WORKS ON FATS IN THE FEED--INTO FATTY
  ACIDS AND GLYCEROL
• BILEProduced by the liver. STORED IN THE GALL
  BLADDER--AIDS INTO THE DIGESTION OF FATS AND
  FATTY ACID. It helps in the action of the enzyme
  of lipase.

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Intestinal Juice

• Glands in the wall of small intestine produce
  intestinal juice.
• Fluids containspeptidase, sucrase, maltase and
  lactaseaids in digestion.
• Proteoses and peptones are broken down by
  peptidase into amino acids.
• Starch and sugars are broken down by sucrase,
  maltase and lactase into simple sugars, glucose,
  fructose and galactose.

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Caecum

• Blind Gutplace where the small intestine and
  large intestine joins
• Little function except the horse/rabbit
• In horsesroughages are digested by bacteria eats
  large amounts of roughages

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Large Intestine

• Shorter in length than the small intestine
• Main function is the absorption of water.
• Small intestine juices still acts on the feed
• Some bacteria works on the feed
• Large intestine adds mucus to enable the material
  to pass through
• Fecesundigested feed not absorbed. Push through
  by muscles in the intestine walls.

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MUST CHEW FOOD AND MIX WITH SALIVA IN THE MOUTH
BEFORE SWALLOWED.

STOMACH CONTAINS ACIDS THAT BREAKS DOWN THE FEED.
CAN NOT BREAK DOWN HAY VERY WELL-DUE TO THE FIBER
IN HAY
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CHICKEN DIGESTION

• TONGUES PUSHES FEED TO GULLET
• GULLET TO THE CROP PRE-DIGESTION
• FEED IS SOFTEN BY SALIVA SECRETIONS
• CROP IS STORAGE
• GIZZARD-CRUSHED AND MIXED
• STOMACH ACTION BY THE MEANS OF JUICESGRIT AND
  GRAVEL ACTION CRUSHES THE FEED.
• SMALL INTESTINE-SITE OF ABSORPTION.MOST
  ABSORPTION OCCURS IN THE LOOP INTESTINES
• CACEAFOUND WHERE THE SMALL INTESTINE JOINS THE
  LARGE INESTINE. FUNCTION UNKNOWN.
• CLOACAENLARGE WHERE THE LARGE INTESTINE JOINS
  THE VENT.
• VENTFECES PASS THROUGH.
• EGGS AND URINE ALSO PASS THROUGH

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VENT
CROP-STORAGE
CLOACA--SMALL INTESTINE VENT JOIN
GIZZARD CRUSHED JUICES
LOOP--MOST ABSORPTION
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Absorption

• Villilines the wall of the small intestine with
  fingerlike projections.
• Villi increase the absorption of the small
  intestine
• Villihas a network of blood capillaries and
  lymph system through which nutrients enter the
  blood system.
• Most food nutrients are absorbed from the the
  small intestine.

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Absorption II

• When absorb Goes from Villiblood
  capillariesliverblood.
• Digested protein forms amino acids
• Starches and sugarsglucose, frutose, and
  galactose
• Fibershort-chained fatty acids
• Digested Fatformed into fats and absorbed by the
  lymph vessel. Carried through the lymphatic
  system, pass through the thoracic duct in the
  neck into the circulatory system.

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Nutrients

• Most nutrients end their journey in the muscle
  cells
• Some nutrients deposit in the live
• Nutrients are used to replace worn out cells and
  build new ones
• Some nutrients are used for energy
• Some nutrients are stored in the form of fat for
  later use.

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METABOLISM

• METABOLISM--SUM OF THE PROCESSES, CHEMICAL
  PHYSICAL OF THE NUTRIENTS BY THE CELLS AFTER THEY
  ARE ABSORBED FROM DIGESTION.
• METABOLISM PROCESS INCLUDE
• ANABOLISM--FORMATION AND REPAIR OF BODY TISSUES
• CATABLOLISM--BREAKDOWN OF BODY TISSUES INTO
  SIMPLE SUBSTANCE AND WASTE PRODUCTS
• OXIDATION--NUTRIENTS PROVIDES ENERGY FOR THE
  ANIMAL.