319 Nutrition

Question: Ingestion?

Digestion?

Absorption?

Elimination?

Answer: Ingestion: act of eating

Digestion: process of breaking down food into molecules small enough for body to absorb

Absorption: taking up small molecules from the digestive compartment

Elimination: undigested material passes out of the digestive compartment

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Question: Why do we use everything on a dry matter basis?

Answer: Cost and nutritive value

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Question: What process can cause cavities, bad breath, flatulence, beer making, body odor, etcetera?

Answer: Fermentation

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Question: Explain the process of fermentation

Answer: Microorganisms + glucose = VFA + CO2

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Question: What are the three structural carbohydrates? Which is completely indigestible to all organisms except fungi?

Answer: Cellulose, hemicellulose, and lignin (indigestible)

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Question: List three highly digestible components inside a plant cell wall

Answer: Protein, sugar, starch, fat

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Question: Lignin in latin translates to…

Answer: Wood

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Question: T/F: As plants mature, they gain more valuable digestible proteins, energy, vitamins, and minerals?

Answer: F: As plants mature, they gain more fiber/lignin as they thicken and become less digestible.

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Question: T/F: During a drought, plants will become less digestible as they increase fiber production to retain water?

Answer: T

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Question: Name the four classes of plant feeds and give an example of each

Answer: Forages: grasses, legumes

Grains: seeds of cereals, linseed plants

Roots: turnips, beets

Byproducts: cereal seed coats, oilseed meals

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Question: Difference between grasses and legumes

Answer: Grasses: corn, timothy, fescue

Legumes: alfalfa, clover, beans, ability to fix atmospheric N2

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Question: What is the name of the N2 fixing bacteria that has a symbiotic relationship with legumes?

Answer: Rhizobium nodules

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Question: T/F: Leaves of a plant are less nutritious, higher in structural carbs, and have more vascular tissue than the stems.

Answer: F: Leaves are more nutritious and lower in structural carbs than stems.

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Question: How do you know how much you should pay for your feed?

Answer: Nutrient density & digestibility

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Question: Difference between in vivo and in vitro

Answer: In vivo: within an animals body

In vitro: trying to replicate the conditions of in vivo

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Question: T/F: Feces are composed of 75% water?

Answer: T

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Question: How does the time of harvest affect the relationship between yield and digestibility?

Answer: Digestibility decreases with increased time until harvest.

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Question: Carbs are essential or nonessential nutrients?

Answer: Nonessential

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Question: Nutrients provide energy for…

Answer: Maintenance, new tissue growth, storage, and protein turnover

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Question: When does hypertrophy of muscles occur?

Answer: When muscle synthesis is greater than muscle breakdown

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Question: T/F: Energy expenditure and muscle mass drives feed intake?

Answer: T

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Question: What is the largest expense on an animal farm?

Answer: The feed

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Question: Explain the process of chemical evaluation of a feedstuff

Answer: Remove the water, boil in NDF to determine amount of structural carbs left behind, then boil in ADF to determine the amount of lignin and cellulose left behind

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Question: What is the purpose of structural carbohydrates?

Answer: Protect, give structure, and reduce water loss

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Question: Explain the process of a laboratory evaluation of a feedstuff

Answer: Measure loss of nutrient from a Dacron bag that has been either incubated in gastric digestion at low pH or in a fistula in a ruminants stomach over various periods of time

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Question: Individual animal assessments don’t work on a farm setting, so how do we measure the efficiency of feed utilization?

Answer: Gain:feed ratio = (ADG)/(Average DM Intake)

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Question: T/F: Females have higher energy requirements than males?

Answer: F: Males have more muscle mass and therefore higher energy requirements than females.

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Question: What do you call a nutrient that must be obtained in the diet because the body cannot make it?

Answer: Essential

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Question: Examples of macro vs micro nutrients?

Answer: Macronutrient: water, carb, protein, lipid

Micronutrient: vitamins and minerals

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Question: Example of a cecal digester and explain the process?

Answer: Rabbits have two types of feces: one is undigested fiber, one is clearance of cecal contents

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Question: Pre-gastric fermenters include ruminants and non-ruminants. Give examples of each.

Answer: Ruminants: cattle, sheep, deer

Non-ruminants: hamster, kangaroo, hippo

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Question: How do non-ruminant pre-gastric fermenters allow for fermentation?

Answer: Sacculated stomach

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Question: Prehension?

Mastication?

Deglutition?

Answer: Prehension: bringing food to mouth

Mastication: chewing food

Deglutition: swallowing

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Question: T/F: Carnivores have a shorter intestine than herbivores because meat is less digestible than plant materials?

Answer: F: Meat is more digestible than plant materials.

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Question: T/F: Large non-ruminants combat digestive inefficiency by eating more?

Answer: T

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Question: What is the name of the animal whose poop is farmed to make $100/cup coffee?

Answer: Asian Palm Civet

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Question: What is the vent of a chicken?

Answer: The common chamber that the digestive, urinary, and reproductive tract open to.

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Question: Can a horse vomit?

Answer: No, their esophagus only allows one-way flow.

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Question: Ruminants have what kind of control over their esophagus?

Answer: Voluntary because they have food that flows up to be re-masticated.

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Question: Why would an animal develop an ulcer?

Answer: They are either producing too much HCl or too little mucus.

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Question: Chief cells secrete pepsinogen, an inactive form of pepsin, that is activated by HCl. Why is it in an inactive state?

Answer: So that we don’t digest ourselves.

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