Nut 115 Final Exam With
Solution
TDN (total digestible nutrients) - ANSWER Old system for calculating energy
content, adds up percent digestible cp, percent digestible crude fiber,
percent digestible nitrogen free extract, and percent digestible ether extract
x2.25
Why and what is ether extract multiplied by when calculating tdn - ANSWER
2.25, because fat has more energy than other nutrients
Disadvantages of tdn - ANSWER Considers only digestive losses, not
expressed in energy units, overestimates energy values of forages
Caloric system - ANSWER considers all energy losses, looks at net energy
Digestible energy - ANSWER Gross energy - fecal energy
Metabolizable energy - ANSWER Digestible energy - energy lost in urine and
gases
Net energy - ANSWER Metabolizable energy minus heat increment
Net energy importance - ANSWER Energy that can be used for maintenance,
growth, and production
Heat increment - ANSWER Energy lost as heat, associated with metabolism
and fermentation
Heat increment of protein, carbs, and fats - ANSWER Protein > carbs > fats
, Heat increment of grains vs forages - ANSWER Grains > forages
Net energy most efficient for what - ANSWER Maintenance
Energy feedstuffs - ANSWER High energy value (TDN>70%), <20% crude
protein
grain characteristics - ANSWER High energy, low in fiber, high in starch, low
to moderate in cp, fair in P and low in Ca
Most important grain - ANSWER Corn, 80% of all grains fed to livestock
Barley - ANSWER 5-6% in crude fiber so limit in swine and poultry diets, high
in protein, usually processed prior to feeding
Oats - ANSWER Limit is swine and poultry due to high fiber, can be fed whole
or processed, safest grain for horses
Sorghum - ANSWER High in tannins
Tannins - ANSWER Make grain astringent and reduce protein digestibility
Considerations with grain quality - ANSWER Foreign material content, starch
content, digestibility, molds/mycotoxins
High moisture when storing grains causes what - ANSWER Caking, heating,
mold
Aspergillus flavis - ANSWER Corn mold, produces aflatoxin, causes liver
damage, impaired growth and reproduction
Solution
TDN (total digestible nutrients) - ANSWER Old system for calculating energy
content, adds up percent digestible cp, percent digestible crude fiber,
percent digestible nitrogen free extract, and percent digestible ether extract
x2.25
Why and what is ether extract multiplied by when calculating tdn - ANSWER
2.25, because fat has more energy than other nutrients
Disadvantages of tdn - ANSWER Considers only digestive losses, not
expressed in energy units, overestimates energy values of forages
Caloric system - ANSWER considers all energy losses, looks at net energy
Digestible energy - ANSWER Gross energy - fecal energy
Metabolizable energy - ANSWER Digestible energy - energy lost in urine and
gases
Net energy - ANSWER Metabolizable energy minus heat increment
Net energy importance - ANSWER Energy that can be used for maintenance,
growth, and production
Heat increment - ANSWER Energy lost as heat, associated with metabolism
and fermentation
Heat increment of protein, carbs, and fats - ANSWER Protein > carbs > fats
, Heat increment of grains vs forages - ANSWER Grains > forages
Net energy most efficient for what - ANSWER Maintenance
Energy feedstuffs - ANSWER High energy value (TDN>70%), <20% crude
protein
grain characteristics - ANSWER High energy, low in fiber, high in starch, low
to moderate in cp, fair in P and low in Ca
Most important grain - ANSWER Corn, 80% of all grains fed to livestock
Barley - ANSWER 5-6% in crude fiber so limit in swine and poultry diets, high
in protein, usually processed prior to feeding
Oats - ANSWER Limit is swine and poultry due to high fiber, can be fed whole
or processed, safest grain for horses
Sorghum - ANSWER High in tannins
Tannins - ANSWER Make grain astringent and reduce protein digestibility
Considerations with grain quality - ANSWER Foreign material content, starch
content, digestibility, molds/mycotoxins
High moisture when storing grains causes what - ANSWER Caking, heating,
mold
Aspergillus flavis - ANSWER Corn mold, produces aflatoxin, causes liver
damage, impaired growth and reproduction
