Overview of nutrition and energetics Flashcards
What is animal nutrition?
The science of how animals assimilate feeds, and how the nutrients in the feeds utilized for growth, tissue repair and replacement, production of animal products. Muti-diciplinary.
What is a nutrient?
Any chemical element or compound in the diet that is required for normal body functions.
Normal functions being: repro, lactation, growth and maintance of life processes
Is a pig a monogastric or a ruminant?
Ruminant.
What is the initial process digestion in the pig mouth?
Amylase breaks downs torch. Peristalsis helps the feed to go down.
Where is bile produced and what does it do?
Bile produced from the liver, emulsifys fats.
What are components of the digestive tract of the pig?
Mouth, esophagus, stomach, small intestine, cecum + conlon (large intestine).
What are the 6 major classes of nutrients?
Carbohyrates, lipids, protein, water, mineral, vitamins
Define food vs feed
Food= anything you can eat that provides nutirents (humans).
Feed= food for animals
Ration
Daily feed portion that you give to an animal
Average breakdown of an animal’s diet
60% water, 16% protein, 20% fat, 4% minerals, <1% carb.
What is an example of digestive enzyme secreted by animal?
Salivary amylase.
Pepsin (stomach).
(small intestine)= Pancreatic amylase and brush border enzymes –>maltase.
What is this the digestive system of?
Role of proventicilus and gizzard?
Chicken
Proventicilus –> Gastric digestion, initiation of digestion.
Gizzard –> Mechanical breakdown, grind the feed.
Basic roles of the omasum, rumen and abomasum?
Omasum is equal to the human stomach
Rumen is the fermenation chamber
Abomasum digestive processes in the ruminant
Groups of microbes in the rumen?
Bacteria, Protezoa, Fungi and Archea.
Relativevely stable population, anaerobic.
What is the main source of E from ruminants?
VFAs
Acetate, butyrate, priopionate
Also production of MP- Bact and prtozoa washed out of the rumen and digested in the small intestine. Major source of AA for ruminants. Synergistic relationship
Where does the portal system go?
Portal system goes to the liver
Where are lipids absorbed into?
Absorbed by the villi. Into the lymphatic system
Decribe the process of the microvilli?
Microvilli are on the surface of the villi. They increase the SA.
Epithelial cells- secrete brush border enzymes to complete carb, protein digestion.
Do rumen papillae secrete enzymes?
What is their role?
The rumen papillae doesn’t secrete enzymes, the papillae absorb the nutrients.
Increase SA, absorb VFAs. Feeds into protal circ.
Where are the major sites for absorbptive processes in rumiants and non-ruminents?
Ruminants= the fore-stomachs (rumen) and small intestine.
Non-ruminants= small intestine.
What are the 3 mechanisms of absorption:
Do they require E?
Diffusion- passive down a [] gradient.
Facilitate diffusion- carrier proteins involved. No E
Active transport- Carrier proteins present, but need E. In form of ATP or Na/K ATPase.
How mcuh of E requirements come from VFAs for cows?
50-80%
What is anabolic vs catabolic?
Anabolic –> BUILDING. Building of complex compounds from small molecules, uses E. ex) Muscle synth.
Catabolic –> Breaking down! The breakdown of molecules into smaller units. Releases E. ex) glycolysis utilized glucose
What is this sequence showing?
The events that occur in t nutrient deficiency.
Will result in a biochem defect. The proteins that are supposed to be synthesized are not.
Functional defect. Missing proteins, cannot proform their function.
Reduced overall performance.
Death if not dealt with.
Energy is…
Energy is NOT A NUTRIENT.
agriculture is important!
What is the animal energy consumption in developed and developing countries?
Developed= overconsumption of E
Developing= lack of resources, unable to provide what is required. Food security issues.
What do we use to meausre gorss energy of feedstuff?
Bomb calorimetry.
GE is heat release when CHO, lipids and proteins in feedstuff are oxidized. In a pressurized env.
We conbust the substrate and measure the heat change of the water.
What are the 4 most important components of the bomb calormieter?
Thermometer, insultaing jacket, bucket and steel bomb.
What are the units you can use to measure E?
Calorie and Joule
Define Gross Energy?
The amount of heat released when a substance (feed) is completely oxidized in a bomb calorimeter.
GE = heat of combusiton.
Why are there higher GE values for fats than protein and carbs?
Fats contain more hydrogen than protein and carbs b/c they are reduced so they contain more hydrogen which more oxygen.
Why are fats more E dense?
Lipids have 2.5x more E than protein and carbs.
What are limitations of GE?
Little about nutritional value.
The contents are burnt.
How much energy will be utilized by the animal? Losses of metabolism
What does fecal E measure?
The energy lost in the feces of the ingested E
What is the single largest loss of ingested E?
Fecal E
What is aparent digestable energy?
Digestable E= Gross E - Fecal E
DE/GE for
pigs
ruminants on concentrate
ruminants on roughage?
DE/GE= 80% for pigs
=70% ruminants on []
=50-60% for ruminants fed roughages
What is metabolizable E (ME)?
It accounts for all additional E losses arising from absorption and metabolism of feed.
Urinary E loss (UE) + gas E loss (GEL) + gill energy loss (GILL) in fish.
ME= DE -(UE + GEL +GILL)
ME= DE x 0.82 in ruminants
What is SF6 tracer used to measure?
Methane production in ruminants.
Sulphur hexfloride.
Metabolizable E formula?
ME= GE - FE- UE - gaseous E (GEL)
What is NE?
NE is net E.
Accounts for E loss as heat during digestion and metabolism.
NE= ME - heat increment (HI).
HI- heat increase after a meal. Heat increment.
NE formula?
NE= GE - FE- UE- GEL- HI
What is net energy used for?
Used for maintainance and then the remainer is used for production.
What are factors that affect heat increment?
Diet digeatibility, level of feeding, diet composition, nutrient utilization
What are the differences in direct and indirect measurement of heat production?
Direct- heat prod measured directly.
Indirect- Use of gas exchange (o2 consumption, co2 output) to estimate heat loss. Open-circuit and Closed-circuit
What are the advantaged and disadvantages of the Net E system?
Advantages: Account for metabolic cost of nutrient metabolim. Allow better prediction of animal performance.
Disadvantage: Expensive, time consuming to measure NE. Hard to collect this data.
Summary of E partitioning visual
:)
What is used for formulating diets (ME vs NE)
Pigs?
Poultry?
Ruminants?
Pigs- NE.
Poultry- ME. Because fecal + urine are excreted together
Ruminants- NE
What are factors that affect TDN?
DM content of feed
Digestability of DM
Amount of fat
Species fed.
Converting TDN to E
1kg TDN = _____ kcal of DE?
1kg TDN = 4.4 kcal of DE
True/False
Energy is the most important nutrient for animals?
False
True/False
Rumen papillae produce important enzymes that facillitate fermentation digestion in the rumen.
False.
Gastric digestion of carbs in pigs yields mostly ______?
Gastric digestion of carbs in pigs yields mostly _Glucose__.
The most important source of E for ruminants that is derived from the GIT is ____?
The most important source of E for ruminants that is derived from the GIT is _VFAs__.
________ is the mechanism of nutrient absportion that requires the expenderature of E.
___Active transport__ is the mechanism of nutrient absportion that requires the expenderature of E.
Gross E - Fecal E - gaseous E - Urinary E = ______?
Gross E - Fecal E - gaseous E - Urinary E = _Metabolizable E__
Maintaince E +Prod E = ______?
Maintaince E +Prod E = __Net E__
What is formed by this glycosidic bond?
What is formed by this glycosidic bond?
