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Chapter 41 Chapter 41 Animal NutritionAnimal Nutrition
Nutritionally Adequate DietNutritionally Adequate Diet
FuelFuel Biosynthesis raw materialsBiosynthesis raw materials Essential nutrientsEssential nutrients
Fueling LifeFueling Life
Balance caloric intake and outputBalance caloric intake and output Excess stored as glycogen and fatExcess stored as glycogen and fat Fat kcal: 9 per gramFat kcal: 9 per gram
Glucose and fat preferred fuel (amino Glucose and fat preferred fuel (amino acids not stored)acids not stored)
Glucose-major fuelGlucose-major fuel Metabolism under hormonal controlMetabolism under hormonal control
Homeostatic Mechanisms(1) When glucose levels rise above a set
point, (2) pancreas secretes insulin into the blood.(3) Insulin enhances the transport of
glucose into body cells and stimulates the liver and muscle cells to store glucose as glycogen, dropping blood glucose levels.
(4) When glucose levels drop below a set point, (5) the pancreas secretes glucagon into the blood.
(6) Glucagon promotes the breakdown of glycogen and the release of glucose into the blood, increasing the blood glucose levels.
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
See page 851—help identify processSee page 851—help identify process
Caloric ImbalancesCaloric Imbalances UndernourishmentUndernourishment:: chronic chronic
caloric deficiencycaloric deficiency
OvernourishmentOvernourishment (obesity):(obesity): excessive food intakeexcessive food intake Leptin-appetite Leptin-appetite
supressing hormonesupressing hormone
MalnourishmentMalnourishment:: essential essential nutrient deficiencynutrient deficiency
Leptin deficient rat on leftLeptin deficient rat on left
Supplying carbon skeletonsSupplying carbon skeletons
Build proteins, carbohydrates, lipidsBuild proteins, carbohydrates, lipids
Essential NutrientsEssential Nutrients
Materials that must be obtained in Materials that must be obtained in preassembledpreassembled form. (Why???) form. (Why???)
MalnourishmentMalnourishment:: essential nutrient essential nutrient deficiencydeficiency
Essential amino acidsEssential amino acids:: 88
Protein deficiency-most Protein deficiency-most common type of common type of malnutritionmalnutrition
•Complete & incomplete proteinsComplete & incomplete proteins•Complementary proteinsComplementary proteins•Limiting amino acids.Limiting amino acids.
Special AdaptationsSpecial Adaptations
Adelei penguins-Adelei penguins-AntarticaAntartica
Use muscle protein Use muscle protein to build new to build new feathersfeathers
Essential fatty acidsEssential fatty acids:: unsaturated fatty acidsunsaturated fatty acids linoleic and alpha-linolenic (linoleic and alpha-linolenic (ΩΩ-3; -3; ΩΩ-6)-6)
phospholipids in cell membranes—phospholipids in cell membranes—esp. nervous tissueesp. nervous tissue
Omega-3 fatty acids have been found to be Omega-3 fatty acids have been found to be beneficial for the heart. Positive effects include beneficial for the heart. Positive effects include anti-inflammatory and anti-blood clotting actionsanti-inflammatory and anti-blood clotting actions, , lowering cholesterol and triglyceride levels, and lowering cholesterol and triglyceride levels, and reducing blood pressure reducing blood pressure
VitaminsVitamins: : many are organic coenzymes (B-vits)many are organic coenzymes (B-vits)
a) water soluble-excreteda) water soluble-excreted
b) fat soluble-stored in adipose b) fat soluble-stored in adipose tissue—can be toxic in excesstissue—can be toxic in excess A,D,E,KA,D,E,K A) Vision-Retinol; skin A) Vision-Retinol; skin D) bone development—rickets—bowed D) bone development—rickets—bowed
legslegs E) antioxidantE) antioxidant K) blood clottingK) blood clotting
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
MineralsMinerals: inorganic cofactors: inorganic cofactors
Calcium: bones, muscle contraction, Calcium: bones, muscle contraction, nerve impulsesnerve impulses
Iodine: goiter: naturally occurring in Iodine: goiter: naturally occurring in marine watermarine water
Iron: oxygen transport (hemoglobin)Iron: oxygen transport (hemoglobin)
Food types/feeding mechanismsFood types/feeding mechanisms OpportunisticOpportunistic HerbivoreHerbivore: eat autotrophs: eat autotrophs CarnivoreCarnivore: eat other animals: eat other animals OmnivoreOmnivore: both: both Feeding AdaptationsFeeding Adaptations Suspension-feedersSuspension-feeders: sift food : sift food
from water (baleen whale)from water (baleen whale) Substrate-feedersSubstrate-feeders: live in or on : live in or on
their food (leaf miner) their food (leaf miner) (earthworm: (earthworm: deposit-feederdeposit-feeder))
Fluid-feedersFluid-feeders: suck fluids from : suck fluids from a host (mosquito); a host (mosquito); hummingbirdshummingbirds
Bulk-feedersBulk-feeders: eat large pieces : eat large pieces of food (most animals)of food (most animals)
Overview of food processing-4 stagesOverview of food processing-4 stages 1-1-IngestionIngestion:: act of act of
eatingeating 2-2-DigestionDigestion: process of : process of
food break downfood break down
enzymatic hydrolysisenzymatic hydrolysis
3- 3- AbsorptionAbsorption: cells : cells take up small moleculestake up small molecules
4- 4- EliminationElimination: removal : removal of undigested materialof undigested material
A)A) intracellularintracellular: breakdown within cells : breakdown within cells (sponges); or within membrane (sponges); or within membrane (paramecium)(paramecium)
B) extracellularB) extracellular: breakdown outside : breakdown outside cells (most animals)cells (most animals)
alimentary canals (digestive tract) alimentary canals (digestive tract)
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
Fig. 41.11
Extracellular Extracellular digestiondigestion
HydraHydra 2 tissue layers2 tissue layers Inner layerInner layerForms digestiveForms digestiveCavityCavity
Incomplete digestiveIncomplete digestiveSystemSystem (only 1 opening)(only 1 opening)
Mammalian digestionMammalian digestion (complete- 2 openings)(complete- 2 openings)
PeristalsisPeristalsis:: rhythmic waves of contraction by rhythmic waves of contraction by smooth musclesmooth muscle
Sphincters:Sphincters: ring-like valves that regulate ring-like valves that regulate passage of materialpassage of material
Accessory glands:Accessory glands: salivary glands; pancreas; salivary glands; pancreas; liver; gall bladderliver; gall bladder
Mammalian digestion: Mammalian digestion: Ingestion & initial digestion Ingestion & initial digestion
Oral cavityOral cavity Mechanical and chemical Mechanical and chemical
digestiondigestion Teeth-reduce size\increase Teeth-reduce size\increase
surface areasurface area ••salivary amylase salivary amylase ••bolusbolus
Pharynx-juncturePharynx-juncture
• •epiglottis-cartilage flap, closes epiglottis-cartilage flap, closes
off trachea when swallowingoff trachea when swallowing
Esophagus—food tubeEsophagus—food tube
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
Fig. 41.14
StomachStomach BolusBolus passes through passes through Cardiac Cardiac Sphincter-Sphincter-enters stomachstomach
(occasional backflow—heartburn)(occasional backflow—heartburn) Preliminary digestion, stores food Preliminary digestion, stores food Mechanical (churning) and Mechanical (churning) and
chemical digestionchemical digestion
gastric juice secreted:gastric juice secreted: Contains HCl & pepsinContains HCl & pepsin
(pepsinogen activated to (pepsinogen activated to pepsin by pepsin by
HCl)-- begins protein digestion HCl)-- begins protein digestion
Positive feedback-Positive feedback-increasingly more pepsin increasingly more pepsin activation activation
Small Intestine: Digestion & Small Intestine: Digestion & Absorption: Absorption: Digestion of carbohydrates, Digestion of carbohydrates,
proteins, nucleic acids, fatsproteins, nucleic acids, fats Acid ChymeAcid Chyme passes through passes through Pyloric SphincterPyloric Sphincter into Small into Small
intestine (duodenum)intestine (duodenum) bilebile: secreted into S.I.: secreted into S.I.
Produced by liverProduced by liver Stored in Gall BladderStored in Gall Bladder Bile salts-emulsifiers ( no enzymes)—break up & coat fatBile salts-emulsifiers ( no enzymes)—break up & coat fat
Some proteases secreted by intestineSome proteases secreted by intestine Pancreas: secretes bicarbonate & enzymesPancreas: secretes bicarbonate & enzymes
Amylases (carbs); lipases (fats); nucleasesAmylases (carbs); lipases (fats); nucleases some proteases secreted in inactive form and activated by some proteases secreted in inactive form and activated by
a membrane-bound enteropeptidasea membrane-bound enteropeptidase
Activation of pancreatic peptidases Activation of pancreatic peptidases within the intestinewithin the intestine
3. Nutrient Absorption3. Nutrient Absorption S.I. highly foldedS.I. highly folded
Villi (finger-like projections) & microvilli Villi (finger-like projections) & microvilli (appendages of villi) increase absorptive (appendages of villi) increase absorptive surface surface
Small vessels in villi absorb:Small vessels in villi absorb: Lipids into the lacteals –to veinsLipids into the lacteals –to veins Other nutrients into Hepatic Portal Other nutrients into Hepatic Portal
Vessel to LiverVessel to Liver
In Lumen-Chylomicrons form: In Lumen-Chylomicrons form: (complex of fat, cholesterol, & (complex of fat, cholesterol, & protein)protein)
Carried by lacteals; dump Carried by lacteals; dump into veins returning to the into veins returning to the heartheart
Other nutrients—travel to liver Other nutrients—travel to liver via Hepatic portal vessel via Hepatic portal vessel
Large intestine Large intestine (colon)-absorb water; (colon)-absorb water; concentrate residueconcentrate residue
Bacterial symbionts-Bacterial symbionts-generate some generate some vitamins—K, biotinvitamins—K, biotin
Cecum-small pouchCecum-small pouch At tip is the AppendixAt tip is the Appendix
FecesFeces Rectum--storageRectum--storage Anus--eliminationAnus--elimination
Large IntestineLarge Intestine
Hormonal Regulation of DigestionHormonal Regulation of Digestion
Gastrin food---> stomach wall ---> gastric Gastrin food---> stomach wall ---> gastric juicejuice
Enterogastrones (duodenum)Enterogastrones (duodenum) 11. Secretin. Secretin - - acidic chyme---> secretin --> pancreas to acidic chyme---> secretin --> pancreas to
release bicarbonate (neutralize chyme)release bicarbonate (neutralize chyme)
2. 2. CholecystokininCholecystokinin (CCK) (CCK) amino/fatty acids---> pancreas to release amino/fatty acids---> pancreas to release
enzymes and gall bladder to release bileenzymes and gall bladder to release bile
Evolutionary adaptationsEvolutionary adaptations Dentition: an animal’s assortment of Dentition: an animal’s assortment of
teethteeth Digestive system lengthDigestive system length
Herbivores-longerHerbivores-longer SymbiosisSymbiosis RuminantsRuminants
Symbionts: koala-- enlarged cecum, symbiotic bacteria ferment finely shredded eucalyptus leaves.
Ruminants—4 stomach chambersRuminants—4 stomach chambers—microbial action—microbial action
Well developed for vegetation: which include deer, cattle, and sheep.