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MILK ENERGETICS
Leo Timms
Iowa State University
ENERGY REACTION VALUES
Reaction type energy value
kcal/mole
1. ATP--- ADP + P 7
UTP--- UDP + P 7
GTP--- GDP + P 7
2. ATP --- AMP + P + P 14
3. NADPH ---- NADP + ~ 3 ATP 21
MILK ENERGETICS 110 LBS. (50 l)
• Protein: 4% or 40 g / liter• 50 liter X 40 g/ l = 2000g synthesized protein• 2000 g /(100 g/ mole) = 20 moles AA in protein
• ENERGY NEEDED:
1. Formation of AA - tRNA: 14kcal / mole
ATP ------ AMP + P + P
2. 2 GTP / AA at ribosome 14 kcal / mole
TOTAL 28 kcal / mole
MILK ENERGETICS 110 LBS. (50 l)
• Fat: 4% or 40 g / liter• 50 liter X 40 g/ l = 2000g fat ( 50% made: 1000)• 1000 g /(256 g/ mole) ~ 4 moles palmitate (C16)
• ENERGY NEEDED:
1. 8 Acetate --- Acetyl CoA: 112 kcal / mole
ATP ------ AMP + P + P
2. 7 Acetyl CoA -- malonyl CoA 49 kcal / mole
3. NADPH ( 21kcal X 7 X 2) 294 kcal / mole
TOTAL 455 kcal / mole
MILK ENERGETICS 110 LBS. (50 l)
• Lactose: 5% or 50 g / liter• 50 liter X 50 g/ l = 2500g lactose• 2500 g /(360 g/ mole) = 7 moles lactose
• ENERGY NEEDED:
1. UTP ----- UDP- Galactose: 7 kcal / mole
UTP ------ UDP + P
2. UDP- galactose ----lactose + UMP 7 kcal / mole
TOTAL 14 kcal / mole
MILK ENERGETICS 110 LBS. (50 l)
Total energy expended for 50 kg milk
Component % moles kcal/m Total kcal %
Protein 4 20 28 560 23
Fat 2 (.5 X 4) 4 455 1820 73
Lactose 5 7 14 100 4
TOTAL 2480
MILK ENERGETICS 110 LBS. (50 l)
Caloric value of 50 kg milk
Caloric value NutritionalComponent grams per gram (kcal) value (kcal)
Protein 2000 4 8000
Fat 1000 ( 2000*) 9 9000 (18,000)
Lactose 2500 4 10,000
* total fat TOTAL 27,000 (36,000)
• ~ 2480 kcal invested to produce 36,000 kcal product!
MATERNAL SUPPORT OF LACTATION
Leo Timms
Iowa State University
MATERNAL LACTATION SUPPORT
MATERNAL LACTATION SUPPORT
• INCREASED DIETARY NUTRIENTS- increased feed intake
- increased GIT size- increased GIT absorptive capacity
• USE OF BODY RESERVES
• COMBINATION
MATERNAL LACTATION SUPPORT
• INCREASED DIETARY NUTRIENTS• rodents
- increased feed intake 300 - 400%- limited capacity to use body reserves
• COMBINATION• cows, goats, pig - extensive
• humans, guinea pigs - minimal/modest• mostly adipose/ some protein + glycogen
MATERNAL LACTATION SUPPORT
•USE OF BODY RESERVES• Elephant seals
* single pup * 28 day lactation* Pup averages 10%/ day BW gain!
* mother doesn’t eat / drink for 28 days• 42% loss in maternal BW
•58% reduction in body fat content• 14 % reduction in body lean weight
Milk Production
• A peak daily milk yield of 15 pounds (about 2 to 2.5 gallons) is not unusual.
• Pigs can easily convert milk – 4.5 lbs of milk= 1 pound of pig
Example: Litter of 10 pigs • Avg. birth weight (3 pounds)• Avg. wean weight (25 pounds)• @ 6 weeks of age
• 10 pigs gain 22 pounds each (220 pounds of total gain)
• Require 990 pounds of milk!
MATERNAL LACTATION SUPPORT
•USE OF BODY RESERVES• Blue whales
* Mother weighs 80,000 kg initially* mother gains 40-55,000 kg (pregnancy)
* single calf * 2500 kg at birth * 7 month lactation
• calf gains 80 - 100 kg / day• mother produces 90 kg milk / day
* mother eats very little for 7 months
MATERNAL LACTATION SUPPORT
•USE OF BODY RESERVES• Blue whales
• How much energy goes into 90 kg whale milk?• Where do nutrients come from if it doesn’t eat?• What is the nutritional value of that 90 kg milk?
• EXTRA CREDIT #4• email answers to me• [email protected]
25 pointsDUE AFTER
SPRING BREAK