Term
True or False
energy is a nutrient |
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Definition
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Term
| What units are used to measure energy? |
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Definition
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Term
| What factors regulate the use of energy? |
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Definition
Feed Quantity/Quality
-amount (affects retention time)
-nutrient content/balance
-digestibility
Animal Characteristics
-feed intake regulation
-genetics
-physiological state
Environment
-temperature, housing etc |
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Term
| What is TDN? What does it measure? |
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Definition
total digestible nutrients
measures relative energy value of a feed
digestible CP + CF + NFE + (EEx2.25) |
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Term
| What are the physiological fuel values for CHO, fat and protein? Do they apply to ruminants? |
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Definition
4 kcal/g
9
4
no, microbial fermentation of CHO into VFA greatly alters this |
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Term
| What does TDN not account for? |
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Definition
energy lost in urine, fermentation, gases, heat etc
doesnt measure vitamins that may provide energy |
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Term
| How is feed energy partitiioned? |
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Definition
GE
DE (loses fecal)
ME (loses urinary & gaseous)
NE (loses HIF)
production & maintenance |
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Term
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Definition
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Term
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Definition
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Term
| Which will have a higher GE, CHO from grain or straw? |
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Definition
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Term
| Is all undigested food undigestible? |
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Definition
| no, fast rate of passage may mean protein passes through to feces |
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Term
| Why does DE over-estimated the value of high-forage diets? |
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Definition
it doesn't account for energy losses associated with digestion (gases, HIF)
forages lose lots of energy as methane & heat |
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Term
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Definition
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Term
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Definition
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Term
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Definition
| DE - (gas energy + urine energy) |
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Term
| Why would you see high ammoounts of allantoin in the urine of some beef cattle? |
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Definition
| if they have a diet high in single cell protein or microbial protein |
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Term
| Which are greater for ruminants, gaseous or urinary losses? |
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Definition
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Term
| What are some forms of heat loss in HIF? |
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Definition
microbial fermentation
nutrient metabolism |
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Term
| If the maintenance requirement of a cow is 4.24kg TDN per day, and the cow is consuming 10kg of a 73TDN% diet, how much of the diet is available for production? |
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Definition
10kg X 0.73 = 7.3kg of TDN
7.3-4.24 = 3.06kg available for production |
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Term
| A diet high in NDF will be (high/low) in energy |
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Definition
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Term
| A diet high in NE/ME will be (high/low) in TDN |
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Definition
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Term
| How much of intake energy is retained? |
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Definition
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Term
| Why is fecal energy greater than heat energy on a high-forage diet? |
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Definition
| less energy in forages is digested (much more energy lost to the feces) |
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Term
Put the following in decreasing order:
lactation energy reqs
gestation energy rews
MER |
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Definition
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Term
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Definition
net energy for maintenance
-basal metabolism, voluntary activity for maintenance, heat to maintain body temp |
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Term
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Definition
NE production
-work, tissue gain, fetus growth etc |
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Term
| What is NEm for beef cattle? |
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Definition
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Term
| High will require more energy per day, a large animal or small? |
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Definition
on a strictly energy-unit basis, large
per unit of BW, small |
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Term
| Which breeds require more energy, bos indicus or bos taurus? |
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Definition
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Term
| Which is greater, MER of bulls or steers/heifers? |
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Definition
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Term
| As environmental temperature approaches UCT or LCT, how is performance affected? |
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Definition
| performance is negatively effected. At high temps intake decreases, MER increases. At LCT intake increases but so does MER |
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Term
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Definition
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Term
| MER increases by ___% during lactation |
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Definition
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Term
| What effect does grazing have on MER? |
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Definition
| can increase requirements by 10-20% depending on terrain, quality, forage availability, distance to water etc |
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Term
| What is compensatory gain? |
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Definition
| overwintering weaned calves on low quality nutrition, then giving high quality diet in spring can increase the ADG above what it would be on a continuous diet |
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Term
| Why does restricting feed reduce the energy requirements of a calf? |
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Definition
| shrinks the GIT, so less energy required to maintain it, reducing metabolic rate |
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Term
| Whih is easier to 'use', fat stores or protein stores? |
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Definition
| fat stores, far more efficient to mobilize energy from them vs muscle |
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Term
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Definition
| amount of energy deposited as non-fat organic matter + energy deposited as fat |
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Term
| Which requires more energy to deposit, fat or protein? |
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Definition
| fat (but it is easier to use/maintain!!) |
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Term
| Why is energy use of visceral tissue so high? |
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Definition
high cell turnover in SI
NA/K ATPase transporters use energy
protein synthesis & turnover
nucleic acid synthesis for cell proliferation |
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Term
| What are bypass nutrients> |
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Definition
| nutrients which aren't fermented in the rumen |
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Term
| Would you want to have bypass CHO nutrients? |
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Definition
| no - limited digestion in the SI so want as much as possible to happen in the rumen |
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Term
| Would you want to have bypass fat nutrients? |
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Definition
for dairy cows, can increase energy supply without affecting microbe populations
for beef cows, could reduce the amount of saturated fats deposited in beef meat (microbes try to saturate the fat) |
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Term
| What is microbial crude protein? |
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Definition
| protein produces by microbes in rumen |
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Term
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Definition
protein that cannot be degraded in the rumen, and therefor is not available for post-ruminal digestion
e.g. heat damaged proteins (maillard rxn) |
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Term
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Definition
degradable intake protein
can be degraded by microbes in rumen |
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