SOCR 320 Exam #2 Study Guide - Brummer
With Complete Solutions
How can nitrogen fertilization promote the occurrence of grass tetany? - ANSWER
Pastures fertilized with nitrogen (N) and potassium (K) fertilizers also are more likely to
induce grass tetany. The plants' uptake of nitrogen and potassium from the fertilizer
further decreases the amount of magnesium available to the animal.
How do carbohydrate reserve levels of grasses compare to legumes? - ANSWER
Legumes carry much greater carbohydrate reserves due to the size of its crown.
What animals are most affected? - ANSWER Older Animals - lactating cows or ewe
What are the primary storage sites of carbohydrate reserves in legumes? - ANSWER
1.Crowns
2.Roots
3.Rhizomes
4.Taproot
What is the average % digestibility of cell contents of ruminants on all forage diets? -
ANSWER 98% for animals on all forage diets
What are the 2 main factors that affect the degradability of the cell wall constituents? -
,ANSWER 1.Crystallinity of cellulose
2.Lignification of the cell wall (Cementing agent)
Why are herbivores well suited to forage diets? - ANSWER the volume of digestive tract
devoted to microbial degradation (2/3)
Horses (other equids) are known as what kind of fiber fermenter? - ANSWER Hindgut
Fiber Fermenter
Cows (other ruminants) are known as what kind of fiber fermenter? - ANSWER Foregut
Fiber Fermenter
How does regurgitation of forage and chewing of cud (bolus) improve forage digestion
in ruminants? - ANSWER Increases the surface area for attachment of bacteria
What happens when excessive amounts of soluble CHOs reach the hindgut of a horse? -
ANSWER They cause lactic acid build-up that can lead to different complications like
colic or founders.
Compared to a ruminant, horses need a diet higher or lower in crude protein? Why? -
ANSWER Yes - most of the amino acids are excreted.
How does the intake and rate of passage of forage through the digestive system
compare between a horse and ruminants? - ANSWER Horses have an active population
, of bacteria and protozoa, similar to rumen. Both breakdown CHO's to create Volatile
Fatty Acids (an important energy source)
Unlike the horse, ruminants perform better on what type of forage? Why? - ANSWER
Ruminants do better on more mush higher quality forage because the bottleneck on a
ruminant is on its rumen, so the faster you can get the forage into their gut the more
gain you will have.
What is the primary source of protein for ruminants? - ANSWER Microbial - microbes get
it from the rumen
Forage utilization limited by N intake if diet less than 6-7% CP - Why? - ANSWER There is
not enough N to maintain microbial population in rumen and reduced digestive capacity
and rate of passage.
At what level of CP in the diet is N wasted? What happens to excess N? - ANSWER 12% -
The excess nitrogen is excess absorbed through rumen wall, some recycled, but most
excreted in urine.
How do ruminants survive on low quality (low CP) diets? - ANSWER N recycles back
through liver and back through the saliva.
How do tannins in certain forages affect protein availability? - ANSWER Tannins bind
with proteins to reduce solubility
With Complete Solutions
How can nitrogen fertilization promote the occurrence of grass tetany? - ANSWER
Pastures fertilized with nitrogen (N) and potassium (K) fertilizers also are more likely to
induce grass tetany. The plants' uptake of nitrogen and potassium from the fertilizer
further decreases the amount of magnesium available to the animal.
How do carbohydrate reserve levels of grasses compare to legumes? - ANSWER
Legumes carry much greater carbohydrate reserves due to the size of its crown.
What animals are most affected? - ANSWER Older Animals - lactating cows or ewe
What are the primary storage sites of carbohydrate reserves in legumes? - ANSWER
1.Crowns
2.Roots
3.Rhizomes
4.Taproot
What is the average % digestibility of cell contents of ruminants on all forage diets? -
ANSWER 98% for animals on all forage diets
What are the 2 main factors that affect the degradability of the cell wall constituents? -
,ANSWER 1.Crystallinity of cellulose
2.Lignification of the cell wall (Cementing agent)
Why are herbivores well suited to forage diets? - ANSWER the volume of digestive tract
devoted to microbial degradation (2/3)
Horses (other equids) are known as what kind of fiber fermenter? - ANSWER Hindgut
Fiber Fermenter
Cows (other ruminants) are known as what kind of fiber fermenter? - ANSWER Foregut
Fiber Fermenter
How does regurgitation of forage and chewing of cud (bolus) improve forage digestion
in ruminants? - ANSWER Increases the surface area for attachment of bacteria
What happens when excessive amounts of soluble CHOs reach the hindgut of a horse? -
ANSWER They cause lactic acid build-up that can lead to different complications like
colic or founders.
Compared to a ruminant, horses need a diet higher or lower in crude protein? Why? -
ANSWER Yes - most of the amino acids are excreted.
How does the intake and rate of passage of forage through the digestive system
compare between a horse and ruminants? - ANSWER Horses have an active population
, of bacteria and protozoa, similar to rumen. Both breakdown CHO's to create Volatile
Fatty Acids (an important energy source)
Unlike the horse, ruminants perform better on what type of forage? Why? - ANSWER
Ruminants do better on more mush higher quality forage because the bottleneck on a
ruminant is on its rumen, so the faster you can get the forage into their gut the more
gain you will have.
What is the primary source of protein for ruminants? - ANSWER Microbial - microbes get
it from the rumen
Forage utilization limited by N intake if diet less than 6-7% CP - Why? - ANSWER There is
not enough N to maintain microbial population in rumen and reduced digestive capacity
and rate of passage.
At what level of CP in the diet is N wasted? What happens to excess N? - ANSWER 12% -
The excess nitrogen is excess absorbed through rumen wall, some recycled, but most
excreted in urine.
How do ruminants survive on low quality (low CP) diets? - ANSWER N recycles back
through liver and back through the saliva.
How do tannins in certain forages affect protein availability? - ANSWER Tannins bind
with proteins to reduce solubility
