NUTR 3000 - Carbohydrates and fibre

Ways of classifying carbohydrates

simple vs complex

soluble (pectin in this category) vs insoluble in water

ADF vs NDF vs CF

ADF include

cellulose and lignin

NDF includes

cellulose, hemicellulose, lignin

Carbohydrates contain what elements

C,H, and O

H and O are in what ratio to each other

2:1

carbohydrates are

sugars or polymers of sugars like starch or cellulose

plants make sugars by

photosynthesis

What carbohydrates are found in the animal body?

Glycogen in the liver and muscles

Glucose in the blood

T/F: Ruminants produce enzymes that can digest carbohydrates

False, their microbes produce those enzymes

The majority of the dry weight of plants (70-80%) is

carbohydrates

Where are carbohydrate digesting enzymes located

mouth

What carbohydrates comprise plant cell contents

Sugars and starches

what carbohydrates comprise the plant cell wall

pectin, cellulose, hemicellulose

What type of plant carbs can animals digest

the cell contents (sugars, starches)

What type of pant carbs can't animals digest (without fermentation)

the cell wall (pectin, cellulose, hemicellulose)

Is pectin water soluble?

Yes (makes gel in jam)

Are sugars soluble?

soluble

Sugars are used by plants ______________

immediately, only some for storage (like sucrose)

Are starches soluble?

less soluble

Starches are used for

storage (reserve in seeds and tubers)

Are fibres soluble

insoluble

Fibres are used for

structure in plants

Give an example of when fibre is a nutrient and an antinutrient

Nutrient=sheep

antinutrient=young chicks

NFE include

readily available carbohydrates

an example of a non-starch polysaccharides is

pectin

Cellulose is a polymer of ___________ with what linkage

glucose with a beta 1,4 linkage

The consequences of a beta 1,4 linkage are

-gives a flat, ribbon-like molecule

-hard to digest

-gives plant tensile strength

T/F: alpha 1,4 linkages are easier to digest than beta 1,4

True

T/F: cows don't have salivary amylase

true. Salivary amylase is more acidic than the rumen environment, therefore they do not have it, it would harm their microbial cultures.

hemicellulose is a polymer of

five carbon sugars in forages that are harder to digest

hemicellulose is found close together with

cellulose

For an alpha 1,4 linkage to be digested it requires __________________________. For a beta 1,4 linkage to be digested, it requires

digestive enzymes

microbial fermentation

Non-starch polysaccharides in plants include

galacturonic acids

rhamnose

lignin is not a

carbohydrate

lignin is a

phenolic polymer

rather than being flexible, lignins are

stiff and brittle

Lignins are used by plants to increase mechanical strength and stiffness because they are strong in

compression

T/F: There are many kinds of lignin

True

three short chain fatty acids (SCFA)

acetate

propionate

butyrate

SCFAs are used for

energy

The end products of digestion and fermentation of cellulose and hemicellulose etc is

SCFA

SCFAs are aka

VFAs

what are the long chain fatty acids

EPA DHA (eye health, brain health, membrane fluidity)

ways to pre treat to make carbs available

cook

extrude ( heat and steam gelatinize starch)

add commercial enzymes

HCL deactivates what enzyme

salivary amylase

fish can digest carbs because they have

long tracts and hundreds of ceca

cow saliva is high in

phosphate buffers

Why dont cows have salivary amylase

because salivary amylase in acididic and saliva has basic phosphate buffers. It is too acidic for rumen environment

pH of rumen, stomach, and salivary amylase

6-6.4

1-2

5.6

SARA stands for

Sub-acute ruminal acidosis

What is Sub-acute ruminal acidosis

Excess fermentation of grains, starches or carbs causing excess metabolites that drop the rumen pH. This causes lameness or laminitis

SI brush border enzymes

galactase (glactose), lactase (lactose), maltase (maltose), Mannase (mannose), fructase (fructose)

What is very easy for microbes to break down, such that animals depend entirely on microbes to digest it

pectins

What animals can't digest starch well

salmonids

Resistant starches are

hard to digest , but intestinal bacteria can break them down

SARA occurs from what kind of diet

high grain low fibre

VFAs are produced by

fermentation

VFAs are absorbed through

rumen epithelium

VFAs are carried from _____________ to _______________

ruminal veins to portal vein in liver