Ch 10 & 11 Flashcards
(31 cards)
Define calorie
A
Define energy
Potential to perform work
Define joule
A
Where is the location of energy in feedstuff?
Energy in covalent bonds
How is energy stored? How efficient is this conversion?
ATP 50%
Define gross energy and digestible energy
Gross energy - heat of combustion
Digestible energy - GE - FE = DE
What is the relative comparison for GE between fats, protein, and carbs?
Fats 9.45
Proteins 5.65
Carbs 4.10
How does TDN compare to DE?
Roughly comparable but TDN is expressed in units of weight or percent
Define metabolizable energy (ME)
DE - UE = ME
Define net energy. How is it related to heat increment (HI)?
NE = ME - HI - HF
How is HI produced?
Metabolism in the liver
How is HI related to the amount of feed intake?
Heat increment depends on the digestibility of the feed. More digestible less HI, less digestible more HI.
How is HI calculated for ruminants?
A
How is heat production related to body weight?
Heat production is high with higher body weight but less per kg as weight increases
Define basal metabolism or basal metabolic rate (BMR). What influences BMR?
Condition in which minimal amount of energy is expended to sustain the body. Factors are age, species, sex
What accounts for up to 50% of the maintenance energy?
Circulation, respiration, liver kidney and nervous functions.
How are BMR and maintenance related?
A
List the macrominerals
Ca, P, Na, Cl, K, Mg, S
How is calcium stored?
Stored in bones and teeth, hydroxy apatate, in blood as a co factor and as a free ion with oxalate
List 3 functions for calcium
Muscle contraction, bone, blood clotting, nervous system
What regulates calcium absorption?
Calcium intake. If you intake more less will be reabsorbed.
Describe how blood calcium levels are maintained.
Calcitonin is released from thyroid when calcium levels are high. PTH is released when calcium levels are low.
Define chelate. Name one for calcium.
Calcium binding agent, oxalate
List three ways calcium is excreted.
Feces, urine, sweat, loss 50% intake
