Microbial Digestion and Metabolism Flashcards
Where does microbial digestion occur in ruminants?
The rumen.
Where does microbial digestion occur in non-ruminants?
The cecum.
What are carbohydrates turned to in the rumen?
VFAs.
What 3 VFAs are produced in the rumen?
- Butyrate (4 Carbons).
- Acetate (2 Carbons).
- Propionate (3 Carbons).
*BAP.
The rumen wall; to the liver via the hepatic portal system.
Where are VFAs absorbed and where are they directed to after absorption?
What is acetate converted into?
Acetyl-CoA.
What are the 3 fates of acetate?
- Energy (Citric acid cycle).
- FA synthesis.
- Ketone bodies.
What is propionate converted into?
Succinyl-CoA.
What are the 2 fates of propionate?
- Glucose (gluconeogenesis).
- Energy (glucose).
What is butyrate converted into?
Beta-hydroxybutyrate.
What is the one fate of butyrate?
Energy (glucose substitute).
What are the characteristics of a roughage?
- Low energy.
- High fiber.
What animals use roughages?
- Ruminants.
- Non-ruminant herbivores.
What are different types of roughages?
- Pasture.
- Silage.
- Hay.
- By-products.
- Crop residues (left over from harvesting plants).
What are the sources of protein in plants?
- Amino acids.
- Ammonia.
- Nitrates.
What is the B vitamin content in forages?
High.
What 2 factors are the mineral composition of plants dependent on?
- Soil mineral content.
- Plant species.
What are the Mg and Ca content in legumes?
High.
What is the P content in grasses and legumes?
P.
What is the general level of K in forages?
High.
What are some examples of cool-season grasses?
- Ryegrass.
- Orchardgrass.
- Tall fescue.
- Timothy.
What two cool-season grasses are affected by ergot?
- Ryegrass.
- Tall fescue.
What does ergot do to animals?
- Damage the tips of extremities.
- Agalactia.
- Prolonged gestation.
- Abortions.
- Retained placenta.
- Fat necrosis (hard clumps of fat constrict internal organs).
What is summer fescue toxicosis?
When animals consume ergot and experience susceptibility to heat stress and a rough hair coat.
What are some examples of warm-season grasses?
- Bermudagrass.
- Bahiagrass.
What do legumes have attached to their roots?
Rhizobia bacteria nodules.
What function does rhizobia bacteria serve?
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.
What are legumes superior to grasses in?
- Protein content.
- Ca content.
- Mg content.
- Energy.
What are some examples of legumes?
- Alfalfa.
- Sweet clover.
- Alsike clover.
- White clover.
- Red clover.
*Not as tolerant of grazing.
What is the danger with feeding animals sweet clover?
It contains the vitamin K antagonist dicumarol, which will inhibit blood clotting.
What does grazing allow animals to do?
Harvest forages.
What are the two types of grazing systems?
- Extensive.
- Intensive.
What is the one method of extensive grazing?
Rangelands.
What are the characteristics of rangeland grazing?
- Large amounts of land.
- Low labor.
- Low upkeep.
What are the three methods of intensive grazing?
- Continuous.
- Rotational.
- Strip.
What are the characteristics of continuous grazing?
- Animals are placed in a pasture and left alone.
- Least labor intensive.
- Lowest cost.
- No pasture rest.
What are the characteristics of rotational grazing?
- Pasture is divided into small areas.
- Animals are moved every few days.
- More labor intensive than continuous grazing.
- Higher cost than continuous grazing.
- Allows for pasture rest.
- Most common.
What are the characteristics of strip grazing?
- Animals are placed on a small strip for grazing.
- Moved to a new strip every day.
- Most labor intensive.
- Highest cost (constant fence moving).
- Allows for pasture rest.
What % moisture is hay dehydrated to?
15% or less moisture/85% or more DM.
What is the goal when harvesting grass to make hay?
To maximize yield and TDN.
What is the best time to harvest grass to make hay?
Around early flower/bloom.
How is silage created?
Anaerobic fermentation of carbohydrates (normally grass).
What is the advantage of silage?
It preserves the nutrients better than hay.
What is the normal % moisture of silage?
65-75% moisture/25-35% DM.
What are two risks when making silage?
- It drying out if stored improperly.
- It molding.
