Ruminant Metabolism

Question 1

where does carbohydrate digestion primarily occur in ruminants? how?

Answer 1

in the rumen; microbes digest carbs into VFAs

Question 2

list the 3 volatile fatty acids and how many carbons each has

Answer 2

1. acetate: 2 carbones
2. proprionate: 3 carbons
3. butyrate: 4 carbons

Question 3

how are VFAs absorbed in ruminats?

Answer 3

through the rumen wall; don;t have to travel through the rest of the tract

Question 4

once absorbed through rumen wall, where do VFAs go?

Answer 4

enter hepatic portal system and go to liver

Question 5

what happens once VFAs get to the liver?

Answer 5

liver converts VFAs to other products for energy

Question 6

what is acetate converted to in the liver and what is it used for (3)

Answer 6

acetate converted to acetyl CoA for

1. fatty acid synthesis
2. citric acid cycle
3. cholesterol synthesis

Question 7

what is proprionate converted to in the liver and what is it used for? (2)

Answer 7

proprionate converted to succinyl CoA for

1. citric acid cycle
2. also is a precursor for glucose in ruminants to maintain blood glucose and provide energy

Question 8

what is butryate converted to in the liver and what is it used for?

Answer 8

butryate is converted to B-hydroxybutyrate, a ketone body that is used for energy in extrahepatic tissues

Question 9

describe energy content of roughages

Answer 9

low in energy

Question 10

what animals are roughages used by? (2)

Answer 10

ruminants and non-ruminant herbivores

Question 11

give 5 generalexamples of roughages

Answer 11

1. pasture
2. hay
3. silage
4. crop residues
5. by-products

Question 12

what do roughages contain to provide protein? (3)

Answer 12

1. amino acids
2. nitrates
3. ammonia

Question 13

describe vitamin content of roughages

Answer 13

B vitamin content is generally high in roughages

Question 14

what does the mineral composition of roughages depend on? (2)

Answer 14

1. plant species

2. soil mineral content

Question 15

decribe calcium and magnesium content in legumes

Answer 15

high

Question 16

describe phosphorous content in legumes and grasses

Answer 16

low

Question 17

describe potassium content in forages

Answer 17

generally high

Question 18

what kind of climate do cool-season grasses prefer?

Answer 18

cool climate (duh)

Question 19

give 4 examples of cool season grasses

Answer 19

1. timothy
2. orchardgrass
3. tall fescue
4. ryegrass

Question 20

what is a deleterious factor of fescue and ryegrass?

Answer 20

they are prone to ergot

Question 21

what is ergot? what does it cause (3)

Answer 21

a fungus of fescue and rygrass that causes

1. loss of tips of extremities
2. abortion and agalactia
3. fat necrosis: hard, large clumps of fat around organs

Question 22

how do you identify ergot infection of ryegrass and fescue?

Answer 22

brown curls on grass

Question 23

what climate do warm-season grasses prefer?

Answer 23

temperatures consistently above 75 degrees

Question 24

give 2 examples of warm season grasses

Answer 24

1. bermudagrass

2. bahiagrass- prefers even warmer temps

Question 25

why are legumes seen as superior forages compared to grasses? (3)

Answer 25

due to their high protein content (nodules) and energy content (leafy) and high in calcium and magnesium

Question 26

why do legumes have such high protein content?

Answer 26

rhizobia bacteria forms nodules that fix nitrogen from the air which is then incorporated into nitrate into the plan and increase crude protein content

Question 27

give 5 examples of legumes

Answer 27

1. alfalfa 2. red clover 3. white clover 4. alsike clover 5. sweet clover

Question 28

what is the most common legume in animal nutrition?

Answer 28

alfalfa

Question 29

what does grazing allow?

Answer 29

allows the animal to harvest the forage themself, bring animals to food source

Question 30

what are the 2 types of grazing systems?

Answer 30

1. extensive: not labor intensive, leave the animals be, leads to animal loss 2. intensive: manage and maintain and check animals, have to move animals because pasture utilization is high so more labor involved

Question 31

list and describe the 3 types of intensive grazing systems

Answer 31

1. continuous grazing: continously stock pasture with animals, low labor but no time for pasture to regrow 2. rotational grazing: animals move to different pasture every few days, more labor but allows pastures to rest some 3. strip grazing: move animals to new strip of pasture every day, usually by moving fences. most labor intensive

Question 32

describe haymaking

Answer 32

dehydrating green forage to a moisture content of 15% or less

Question 33

what is the issue with hay?

Answer 33

it is hard to get a decent yield with both volume and nutrition

Question 34

what will younger hay yield

Answer 34

higher TDN, but lower total volume yield

Question 35

what will older hay yield?

Answer 35

higher fiber, lower TDN, higher total volume yield

Question 36

what do most people try to do when making hay?

Answer 36

maximize TDN with yield by harvesting in the early bloom/early flower stage

Question 37

how is silage created?

Answer 37

anaerobic fermentation of carbohydrates

Question 38

with is the dry matter content of silage, what does this mean?

Answer 38

only 25-35% DM, very high water content, wet product