Lipid Use and Metabolic Disorders

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Lipid Use and Metabolic Disorders
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Fatty Acid Profile

• Major fatty acids in feed fats
• C160 Palmitic acid
• C161 Palmitoleic acid
• C180 Stearic acid
• C181 Oleic acid
• C182 Linoleic acid
• C183 Linolenic acid
• Unsaturatedsaturated ratio
• C161 C181 C182 C183
• C160 C180

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Types of Feed Fats and Oils

• Oils
• Vegetable oils
• Soapstocks FA salt ion (Na, K)
• Fats
• Tallow, lard
• Choice white grease
• Restaurant grease
• Blends
• Oils fats

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Fat Sources

• Oil sources
• Soapstock
• Vegetable oil
• Restaurant grease
• Fat sources
• Pig and cattle tissues from
• Slaughter plants, lockers
• Grocery stores
• Deadstock

Age of oil/heat damage? free fatty
acids? Hydrogenated oil (trans fatty acids)?
Variation due to US ratio free-fatty
acids Others
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Age and Energy Values (Poults)
Fat digestibility increases with age
ME (kcal/lb)
Age (weeks)
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US Ratio and Energy Values
1) Saturated FA are not digested as well as
unsaturated FA
ME (kcal/lb)
UnsaturatedSaturated ratio
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US Ratio and Energy Values
ME (kcal/lb)
Young
Old

• Saturated FA are not digested as well as
  unsaturated FA
• The situation is worse for young animals

Wiseman et al. (1991)
UnsaturatedSaturated Ratio
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Free Fatty Acids and Energy Values
Old
Young
ME (kcal/lb)
1) FFA are not digested as well as TGs 2) The
problem is worse in young animals
0 10 20 30 40 50 60 70 80 90
100 Free Fatty Acids ()
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Heat Damage and Energy Values
ME (kcal/lb)
Heating time at 360F (hrs)
Heat damage progressively reduces the feeding
value of restaurant grease
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Fat Deficiency

• Carnivore diets with under 5 total fat can
  induce essential fatty acid deficiencies
• Symptoms include dull hair coat, reproductive
  failure (testicular underdevelopment, anestrus,
  and lack of libido), and dry, scaly skin
• Adding essential fatty acids to diets with over
  15 total fat not beneficial
• Essential fatty acids only required at 1 of
  diet
• Birds on deficient diet show poor feathering
• Difficult to create deficiency in ruminants or
  cecal fermenters (caprophagy)
• Microbes synthesize adequate amounts of fats

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Lipid Supplementation of Diets

• Advantages
• Increases energy density
• Low heat increment (ruminants)
• Decreases dust
• Increases pellet quality
• Lubricates machinery
• Disadvantages
• Decreases milk fat (ruminants)

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Tolerance of Fats in Diets

• Horses can tolerate fat levels up to 20 of their
  diet
• Dogs can tolerate up to 40 fat in diet
• Ruminants can only tolerate 7-8 fat in diet,
  because more than that adversely affects microbes
  and decreases feed consumption and fiber
  digestion
• Can be fed more if fed as bypass fat
• EXCEPTION Newborn ruminants can be fed over 30
  fat diets - essentially a monogastric species

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Over-feeding Fats

• Overfeeding fats leads to more fat deposition
  than overfeeding carbohydrates
• 95 of extra energy deposited as fat compared to
  75 for carbohydrate overfeeding
• Shorter chain fatty acids (not included in
  lipoproteins and chylomicrons) have effects
  closer to carbohydrates
• Induction of fatty liver
• Hyperplasia and hypertrophy of pancreatic islets
  cells
• Early indications of diabetes mellitus
• Impaired memory and learning functions!!!

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Impaired Lipid Digestion or Absorption

• Pancreatic disorders
• Liver disorders
• Small intestinal problems
• Causes steatorrhea
• Excessive fat in feces (grey color, greasy
  appearance)
• Most frequently seen in companion animals

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CLA Conjugated Linoleic Acid

• Related to linoleic acid (182)
• CLA is 184
• Produced by rumen organisms
• Cellulolytic bacteria
• Source
• Ruminant products
• Meat
• Milk

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Conjugated Linoleic Acid
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CLA - Conjugated Linoleic Acid

• Naturally trans double bond
• ONLY made by microbes
• CLA levels are higher in grass fed ruminants (and
  kangaroos or other foregut fermenters)
• Not in hindgut fermenters!!
• Wide range of proposed benefits
• Lean muscle gain, decreased fat deposition,
  inhibitory for inflammatory mediators and tumors
• Cannot be utilized by liver enzyme D-6-D in
  prostaglandin synthesis
• Block prostaglandin production and reduce
  inflammatory responses

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Conjugated Linoleic Acid
trans 10, cis 12 CLA
cis 9, trans 11 CLA
linoleic acid
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Metabolic Disorders

• Impairment of liver function can alter lipid
  metabolism
• Infectious disease, genetic disorders
• Other drugs or compounds
• Large number of metabolic disorders associated
  with lipid metabolism
• Genetic usually appear at birth, fatal
• Tay-Sachs is ONE example

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Tay-Sachs

• Autosomal recessive trait
• Accumulation of gangliosides (fatty acid
  derivatives) in CNS neurons
• Lack enzyme that breaks down lipids
• Gangliosides accumulate, destroy function of
  neurons, and eventually destroy neurons
  themselves

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Infantile Tay-Sachs

• Most common variant
• Appear normal at first, but by 6 months of age
  affected infants become blind, deaf, unable to
  swallow, muscles atrophy and eventually become
  paralyzed
• Death before age 4 in most cases
• Juvenile onset and adult onset variants also exist

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Metabolic Disorder Fatty Liver
Negative energy balance
Rapid mobilization of adipose tissue
Liver can not efficiently utilize fats
Liver stores fat, produces ketones
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Hyperlipemia

• Horses and ponies, llamas and alpacas
• Similar to ketosis in cattle
• Mobilization of body fats and incomplete
  oxidation leading to excess ketones in blood
• Occurs with poor feed intake in conjunction with
  high energy demand (pregnancy, lactation, stress)
• Higher frequency in obese animals

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Fatty Liver

• Consequences
• Impaired liver function
• Increased incidence of disease
• Decreased fertility
• Prevention
• Increase diet energy density prior to parturition
• Do not over-condition animals prior to
  parturition

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Ketosis/Pregnancy Toxemia

• Adipose response to low blood glucose

Free fatty acids (FFA) released
Low blood glucose
Fat reserves mobilized
Partial oxidation of FFA to ketone bodies
Liver uptake of FFA
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Ketosis

• Dairy cows
• Pregnant ewes

• Occurs most often following calving
• Increased glucose demands to support lactation
• Body fat is mobilized to meet energy demands,
  but
• TCA cycle backs up
• Over conditioned cows

• Last third of gestation
• Fetus takes up space and reduces capacity of
  intestine
• Caused by inadequate energy intake
• Mortality can be as high as 80
• Twin lamb disease

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Acetone
Ethyl Alcohol
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High-Protein, High-Fat Diets

• Used as a dieting tool by some people
• Relies on extremely low intakes of carbohydrates
  very little glucose absorbed
• Use fat and protein as primary energy sources
• Monitor ketones when ketones elevated enough,
  diet is successful
• Why does this work??
• What are consequences??

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Fat Replacers

• Simpless
• Protein based fat replacement
• Made of egg white, milk protein or whey
• Not suitable for baking or frying
• Olestra
• Made from sucrose and fatty acids
• 1 oz bag of chips zero fat and 70 kcal
• Regular bag of chips 10 gms fat and 150 kcal
• Side effects abdominal cramps and diarrhea,
  fecal incontinence