ANSC 221 Exam 2 Questions with Verified Correct
Answer
where is fat digested, primarily, and how? What is needed to do a good job?
1. occurs in small intestine
2. bile needed to do a good job because it emulsifies that fat which allows enzymes that digest fat
to get to it more easily
Why don't the protein digesting enzymes digest the cells that make them?
pepsin is in inactive form when secreted
how is carbohydrate digestion different between ruminant and non-ruminant animal
1. ruminants: the CHO digestion occurs by bacterial metabolism and they are converted to VFA's
which are directly absorbed into the blood stream and account for a huge percentage of the
energy consumed
2. non ruminants: they are converted to disaccharides and then to monosaccharides in the cell
and then used for energy.
how is digestion of protein different in the ruminant than the non ruminant?
1. non ruminant: digestion occurs by pepsin and other pancreatic enzymes secreted in small
intestine
2. ruminant: microbes break down, remodel, and manufacture essential amino acids and utilize
NPN
NPN
,nonprotein nitrogen
why is NPN useless to non-ruminants
it is absorbed in the small intestine and excreted via the kidney, rather than being available in the
cecum where it's needed
method to determine value of feedstuff
proximate analysis
TDN
1. total digestible nutrients
2. index of energy on carbohydrate bases
3. digestible CP + digestible CF + digestible NFE + digestible EE (2.25)
how do we determine value of feedstuff proteins
determining digestibility and biological value
gross energy
1. all energy in a feed
2. not all available to an animal
3. depends on how much heat is liberated upon combustion
digestible energy
1. energy that does not end up in feces
2. absorbed by animal
3. not all used by animal, some is lost
, metabolizable energy
1. energy that is left over after accounting for energy in feces, urine, and gases
2. still not all available for animal to use
net energy
1. energy that is left after accounting for losses to feces, urine, gases, and heat increment
2. energy that is amiable for animal to use
heat increment
energy lost in fermentation and metabolic process
why is fat of more value in the summer when it's hot?
fat has a lower heat increment than carbs
how could 2 feeds have same TDN and DE values but be of different energy use to the
animal?
2 feed have different digestibility
how could a feed have little protein value even though it has a high biological value
feed has a low digestibility
how could a feed have little protein value even though it's digestibility is high
feed has a low biological value
what does biological value depend on
essential amino acid balance
Answer
where is fat digested, primarily, and how? What is needed to do a good job?
1. occurs in small intestine
2. bile needed to do a good job because it emulsifies that fat which allows enzymes that digest fat
to get to it more easily
Why don't the protein digesting enzymes digest the cells that make them?
pepsin is in inactive form when secreted
how is carbohydrate digestion different between ruminant and non-ruminant animal
1. ruminants: the CHO digestion occurs by bacterial metabolism and they are converted to VFA's
which are directly absorbed into the blood stream and account for a huge percentage of the
energy consumed
2. non ruminants: they are converted to disaccharides and then to monosaccharides in the cell
and then used for energy.
how is digestion of protein different in the ruminant than the non ruminant?
1. non ruminant: digestion occurs by pepsin and other pancreatic enzymes secreted in small
intestine
2. ruminant: microbes break down, remodel, and manufacture essential amino acids and utilize
NPN
NPN
,nonprotein nitrogen
why is NPN useless to non-ruminants
it is absorbed in the small intestine and excreted via the kidney, rather than being available in the
cecum where it's needed
method to determine value of feedstuff
proximate analysis
TDN
1. total digestible nutrients
2. index of energy on carbohydrate bases
3. digestible CP + digestible CF + digestible NFE + digestible EE (2.25)
how do we determine value of feedstuff proteins
determining digestibility and biological value
gross energy
1. all energy in a feed
2. not all available to an animal
3. depends on how much heat is liberated upon combustion
digestible energy
1. energy that does not end up in feces
2. absorbed by animal
3. not all used by animal, some is lost
, metabolizable energy
1. energy that is left over after accounting for energy in feces, urine, and gases
2. still not all available for animal to use
net energy
1. energy that is left after accounting for losses to feces, urine, gases, and heat increment
2. energy that is amiable for animal to use
heat increment
energy lost in fermentation and metabolic process
why is fat of more value in the summer when it's hot?
fat has a lower heat increment than carbs
how could 2 feeds have same TDN and DE values but be of different energy use to the
animal?
2 feed have different digestibility
how could a feed have little protein value even though it has a high biological value
feed has a low digestibility
how could a feed have little protein value even though it's digestibility is high
feed has a low biological value
what does biological value depend on
essential amino acid balance
