Exam 1 Flashcards
As forage advances in maturity (from early age to lat e maturity), what happens to its concentration of:
a) fiber,
b) energy,
c) protein
a) fiber increases
b) energy decreases
c) protein decreases
this makes the forage less digestible as is matures, because as fiber increases, digestibility decreases
What is “Grass tetany”? Explain.
Grass tetany is a deficiency in Magnesium.
This happens during cool, cloudy weather in the early spring or late winter.
It can be very bad for the animal and even cause death.
Mature animals are more likely to be affected, particularly lactating females.
What are NDF and ADF? Compare them.
NDF: Neutral Detergent fiber, composed of Hemicellulose, Cellulose, and Lignin
ADF: Acid Detergent fiber, composed of cellulose and lignin making it less digestible than NDF
Why do we like to feed fats to livestock? Explain.
Fats have 2.25% more energy than carbs
Fats can help keep the dust down and can increase palatability.
What happens to an N containing feed (soybean meal or urea) as it enters the GI tract of cattle? Explain.
Urea Production
Ammonia is used for microbial protein
N-containing feed can be recycled back through the animal, or can be excreted out if there is excess urea in the animal
What are the two most commonly fed carbohydrates in livestock nutrition? Give two examples for each. How do they differ?
Starch: (cellulose, hemicellulose) molassa, grain, cornstalks
Fiber: (cellulose, hemicellulose, lignin) wheat, alfalfa
Starch is more available and easier to digest than Fiber.
What does RFV stand for? Explain its importance and application. How do you determine RFV?
Relative Feed Value
RFV = (digestible DM% * DM intake %)
This is a method of determining the value of hay based on NDF and ADF content
What does “Biological Value” (BV) show? How do you determine this?
BV is the portion of AAs that is actually retained by the animal.
BV of a protein source depends on 2 factors:
(1) how well the animal converts proteins to AAs
(2) Ending AA balance compared to the animal’s AA requirement
Excess consumption of iron can cause zinc, copper, manganese, and selenium absorptions to be:
a. only affect zinc absorption
b. increased
c. decreased
d. not affected
c. decreased
Which one is the most energy efficient VFA?
a. acetic acid
b. propionic acid
c. butyric acid
d. lauricacid
b. propionic acid
The most expensive macro-nutrient (per weight) to feed is _____.
a. protein
b. carbohydrates
c. fat
d. calcium
a. protein
The Ca:P ratio for growing animals and lactating is _____ and for laying hens is _____.
a. 1.2 to 1.5:1, 6:1
b. 2:1, 4:1
c. 6:1, 1.2 to 1.5:1
d. 3:1, 2:1
a. 1.2 to 1.5:1, 6:1
Acute “hypomagnesemia” or “grass tetany” can be caused by the following except:
a. high dietary Ca
b. low soil P
c. low forage K
d. low forage Mg
c. low forage K
Too much grain in a ration fr ruminants causes the rumen pH to first be _____:
a. unchanged
b. increased
c. depends on the day light duration
d. decreased
d. decreased
Feeding fats in ration will: a increase energy density b. increase absorption of vitamin A c. may decrease fiber digestion d. all of the above
d. all of the above
In the rumen the interaction between Mo and S form thiomolybdates which are absorbed if:
a. adequate amounts of Cu is present
b. adequate amounts of S is present
c. low amounts of Cu is present
d. adequate amounts of Mo is present
c. low amounts of Cu is present
Excess NH3 is first:
a. excreted in the urine
b. recycled through the liver
c. recycled through the rumen
d. excreted in the feces
b. recycled through the liver
Feeding ionophores can be beneficial because:
a. acetate production decreases
b. feed:gain decreases
c. propionate production decreases
d. methane production decreases
b. feed:gain decreases
Which one is a factor that influences metabolic evaluation of protein utilization in a ruminant?
a. diffusion of ammonia from the rumen
b. muscle turnover
c. overfeeding protein
d. all of the above
d. all of the above
How would you assess to see whether or not you are over feeding protein?
a. urinary nitrogen content
b. fecal nitrogen content
c. milk urea nitrogen content
d. all of the above
d. all of the above
When evaluating the protein content of a feed, why would you want to know its amino acid profile?
a. amino acids are necessary energy substrates for protein synthesis
b. protein synthesis will decrease when a required amino acids is inadequately supplemented
c. protein synthesis will increase when a required amino acids is inadequately supplemented
d. you would not need to. protein synthesis is independent of amino acid requirements
b. protein synthesis will decrease when a required amino acids is inadequately supplemented
Which feedstuff has the greatest biological value for protein?
a. blood meal
b. soybean meal
c. egg albumin
d. fish meal
c. egg albumin
Which one is NOT a component of determining metabolizable energy requirement for an animal?
a. gas energy
b. fecal energy
c. heat increment
d. urine energy
a. gas energy
Why is a ruminant less energy efficient than a non-ruminant?
a. ruminants can not absorb nutrients efficiently
b. ruminants eat rations with lower energy per kg
c. ruminants lose energy through methane production and heat of fermentation
d. ruminants digest feed in more than one location
c. ruminants lose energy through methane production and heat of fermentation
