Growth and Muscle Composition

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Growth and Muscle Composition

• Page 61

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Typical Growth Curve
Growth Units
Time
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Typical Growth Curve
Growth Units
Lag
Time
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Typical Growth Curve
Growth Units
Log
Lag
Time
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Typical Growth Curve
Stationary
Growth Units
Log
Lag
Time
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• Where on this curve would protein deposition
  occur?

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Typical Growth Curve
Growth Units
Protein
Time
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• Where on this curve would fat deposition occur?

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Typical Growth Curve
Fat
Growth Units
Protein
Time
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Average Age at Slaughter

• Beef 18 - 24 months
• Pork 20 - 24 weeks
• Broilers 6 - 7 weeks
• Turkeys 12 - 14 weeks

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Effect of Age on Carcass Composition

• The more physiologically mature an animal is at
  the time of slaughter, the fatter it is THEREFORE
  as the animal gets older, it deposits fat instead
  of protein

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Typical Growth Curve
Beef
Growth Units
Pork
Turkey
Chicken
Time
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Effect of Age on Carcass Composition

• Which would be fatter due to maturity?
• Beef or Chicken?

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Avg. Proximate Comp. of Muscle Tissue

• Definition This is the Percent protein,
  moisture, fat and ash in muscle

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Avg. Proximate Comp.of Muscle Tissue
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Differences B/W Species (why is chicken a little
less fat?)

• Effect of maturity
• Increased physiological maturity causes excess
  fat
• Genetic selection for leanness and muscling
• Quality grading system only includes conformation
  and not fat

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Nutritive Value of Meat
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Advantages of Muscle Foods / Meat in the Diet

• What are the advantages of
• meat in the diet?

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A Protein

• Meat provides 43 of the protein we consume

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Animal Proteins are High Quality (3 reasons why)

• Protein Dense
• High in Essential Amino Acids
• Bioavailable

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B Vitamins

• Meat is high in the water soluble vitamins
  (remember these ???)

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Vitamins From Meat

• Niacin 47
• Riboflavin 30
• Thiamin 28
• Vitamin A (not WS) 20
• Vitamin B6 41
• Vitamin B12 78

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C Minerals

• Meat is a good source of the minerals
• Iron (Fe) 30
• Magnesium (Mg) 14
• Zinc (Zn) 47

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Concerns Related to (Muscle Foods/Meat) in the
Diet

• What are the concerns?

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Total Fat

• 33 of total fat in our diet comes from meat
  products
• 47 of total fat comes from animal products

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Saturated Fats

• 45 of our dietary saturated fats come from meat
  products
• 68 of total dietary saturated fats come from
  animal products
• Why are saturated worse? They are harder to
  break down

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Cholesterol

• All of our dietary cholesterol comes from animal
  products
• 40 of cholesterol comes from meat products

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Dietary Cholesterol
Cholesterol