Microbial Digestion and Metabolism

Question 1

Where does microbial digestion occur in ruminants?

Answer 1

The rumen.

Question 2

Where does microbial digestion occur in non-ruminants?

Answer 2

The cecum.

Question 3

What are carbohydrates turned to in the rumen?

Answer 3

VFAs.

Question 4

What 3 VFAs are produced in the rumen?

Answer 4

1. Butyrate (4 Carbons).
2. Acetate (2 Carbons).
3. Propionate (3 Carbons).
   *BAP.

Question 5

The rumen wall; to the liver via the hepatic portal system.

Answer 5

Where are VFAs absorbed and where are they directed to after absorption?

Question 6

What is acetate converted into?

Answer 6

Acetyl-CoA.

Question 7

What are the 3 fates of acetate?

Answer 7

1. Energy (Citric acid cycle).
2. FA synthesis.
3. Ketone bodies.

Question 8

What is propionate converted into?

Answer 8

Succinyl-CoA.

Question 9

What are the 2 fates of propionate?

Answer 9

1. Glucose (gluconeogenesis).
2. Energy (glucose).

Question 10

What is butyrate converted into?

Answer 10

Beta-hydroxybutyrate.

Question 11

What is the one fate of butyrate?

Answer 11

Energy (glucose substitute).

Question 12

What are the characteristics of a roughage?

Answer 12

1. Low energy.
2. High fiber.

Question 13

What animals use roughages?

Answer 13

1. Ruminants.
2. Non-ruminant herbivores.

Question 14

What are different types of roughages?

Answer 14

1. Pasture.
2. Silage.
3. Hay.
4. By-products.
5. Crop residues (left over from harvesting plants).

Question 15

What are the sources of protein in plants?

Answer 15

1. Amino acids.
2. Ammonia.
3. Nitrates.

Question 16

What is the B vitamin content in forages?

Answer 16

High.

Question 17

What 2 factors are the mineral composition of plants dependent on?

Answer 17

1. Soil mineral content.
2. Plant species.

Question 18

What are the Mg and Ca content in legumes?

Answer 18

High.

Question 19

What is the P content in grasses and legumes?

Answer 19

P.

Question 20

What is the general level of K in forages?

Answer 20

High.

Question 21

What are some examples of cool-season grasses?

Answer 21

1. Ryegrass.
2. Orchardgrass.
3. Tall fescue.
4. Timothy.

Question 22

What two cool-season grasses are affected by ergot?

Answer 22

1. Ryegrass.
2. Tall fescue.

Question 23

What does ergot do to animals?

Answer 23

1. Damage the tips of extremities.
2. Agalactia.
3. Prolonged gestation.
4. Abortions.
5. Retained placenta.
6. Fat necrosis (hard clumps of fat constrict internal organs).

Question 24

What is summer fescue toxicosis?

Answer 24

When animals consume ergot and experience susceptibility to heat stress and a rough hair coat.

Question 25

What are some examples of warm-season grasses?

Answer 25

1. Bermudagrass. 2. Bahiagrass.

Question 26

What do legumes have attached to their roots?

Answer 26

Rhizobia bacteria nodules.

Question 27

What function does rhizobia bacteria serve?

Answer 27

It fixes nitrogen from the atmosphere and converts it into nitrates for use by the plant. *Why nitrogenous fertilizer should not be used on legumes.

Question 28

What are legumes superior to grasses in?

Answer 28

1. Protein content. 2. Ca content. 3. Mg content. 4. Energy.

Question 29

What are some examples of legumes?

Answer 29

1. Alfalfa. 2. Sweet clover. 3. Alsike clover. 4. White clover. 5. Red clover. *Not as tolerant of grazing.

Question 30

What is the danger with feeding animals sweet clover?

Answer 30

It contains the vitamin K antagonist dicumarol, which will inhibit blood clotting.

Question 31

What does grazing allow animals to do?

Answer 31

Harvest forages.

Question 32

What are the two types of grazing systems?

Answer 32

1. Extensive. 2. Intensive.

Question 33

What is the one method of extensive grazing?

Answer 33

Rangelands.

Question 34

What are the characteristics of rangeland grazing?

Answer 34

1. Large amounts of land. 2. Low labor. 3. Low upkeep.

Question 35

What are the three methods of intensive grazing?

Answer 35

1. Continuous. 2. Rotational. 3. Strip.

Question 36

What are the characteristics of continuous grazing?

Answer 36

1. Animals are placed in a pasture and left alone. 2. Least labor intensive. 3. Lowest cost. 4. No pasture rest.

Question 37

What are the characteristics of rotational grazing?

Answer 37

1. Pasture is divided into small areas. 2. Animals are moved every few days. 3. More labor intensive than continuous grazing. 4. Higher cost than continuous grazing. 5. Allows for pasture rest. 6. Most common.

Question 38

What are the characteristics of strip grazing?

Answer 38

1. Animals are placed on a small strip for grazing. 2. Moved to a new strip every day. 3. Most labor intensive. 4. Highest cost (constant fence moving). 5. Allows for pasture rest.

Question 39

What % moisture is hay dehydrated to?

Answer 39

15% or less moisture/85% or more DM.

Question 40

What is the goal when harvesting grass to make hay?

Answer 40

To maximize yield and TDN.

Question 41

What is the best time to harvest grass to make hay?

Answer 41

Around early flower/bloom.

Question 42

How is silage created?

Answer 42

Anaerobic fermentation of carbohydrates (normally grass).

Question 43

What is the advantage of silage?

Answer 43

It preserves the nutrients better than hay.

Question 44

What is the normal % moisture of silage?

Answer 44

65-75% moisture/25-35% DM.

Question 45

What are two risks when making silage?

Answer 45

1. It drying out if stored improperly. 2. It molding.