Manipulating the fatty acid composition including CLA content of animal products

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Manipulating the fatty acid composition including
CLA content of animal products

• Professor, Dr. Peter Buttery
• Division of Biochemistry Nutrition
• Biosciences School
• The University of Nottingham UK

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Why Manipulate the fatty acid composition of
animal products?

• To reduce the intake of bad fatty acids by the
  consumer
• To increase the intake of good fatty acids by
  the consumer
• To increase sales of such products by improving
  their image

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Dietary Reference Values for Fatty
AcidsPopulation averages ( total energy)1991
Saturated Fatty Acids 10 Cis polyunsaturated
fatty acids 6 Cis monounsaturated fatty
acids 12 Trans fatty acids 2 Total Fatty
Acids 30
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Further Recommendations1994
Population average consumption of long chain n-3
polyunsaturated fatty acids should double (from
0.1g/day to 0.2g/day (not going to discus this
here but is important)
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Saturated fatty acid (SFA) intake in Great Britain
target
Source National Food Survey 2000
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Contribution of Animal Products to Saturated
Fatty Acid (SFA) Intake in Great BritainNational
Food Survey 2000
Other 39
Dairy 39
Meat 22
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• Meat contributes about 22 of total and
  saturated fat intake in the human diet
• Lamb has a high stearate content which gives a
  waxy texture, producing poor organoleptic
  properties
• Red meat, as part of a balanced diet, is an
  important source of protein and iron

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Possible Approaches

• Change fatty acid profile of diet low fat
  diet biohydrogenation of unsaturated fat
• Protected fatty acids
• Manipulation of de novo fat synthesis that is
  reduce the fat content of the carcass

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Reduction of fat

• Breeding
• Diet
• Growth Hormone
• Beta agonists
• CLA?
• Not legal in Europe but are in many parts of the
  world----China?

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Fatty acid composition of intramuscular fat in
pigs fed different oils
Entire male LandraceLarge White Pigs (3 per
group) were grown from 55kg to 120kg LF diet no
added fat SO diet 43.5g/kg sunflower oil
31.5g/kg rape seed oil RO diet 75g/kg rape seed
oil Budd, Salter, Buttery Wiseman, unpublished
data
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THE RUMINANT

• Fats over 10 cause problems with rumen function
• Unsaturated fats are hydrogenated in the rumen so
  difficult to alter the diet.

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Adipose Tissue Fatty Acid Deposition in Ruminant
Adipose Tissue
DIET
DE NOVO SYNTHESIS
C181/C182/C183
C160
C180
C180
Rumen
C181
Adipose Tissue
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Fatty acid composition abomasal fluid and adipose
tissue of sheep fed on grass nuts
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Sources of Ruminant Milk Saturated Fatty Acids
Mammary Gland
Acetate/ ?-OH Butyrate
C160
C40-C140
C180
C181
Diet
Adipose Tissue
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Comparison of the fatty acid composition of
duodenal fluid and milk from cows
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Fatty acid synthesis in adipose tissue mammary
gland
MAMMARY
ADIPOSE
Acetyl CoA
Acetyl CoA
Acetyl CoA Carboxylase (ACC)
Malonyl CA
Malonyl CA
Fatty Acid Synthase (FAS)
C160
C160
Elongase
C180
C180
Stearoyl CoA Desaturase (SCD)
C181
C181
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Correlation between SCD mRNA and oleate content
of omental adipose tissue of growing sheep
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Effect of insulin on SCD gene expression oleate
synthesis in ovine adipose tissue explants
Ins 20nM Insulin Dex 10nM Dexamethosone
cont ins dex ins dex
cont ins dex ins dex
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Effect of feeding forage or concentrate-based
diets on acetyl CoA carboxylase(ACC) stearoyl
CoA desaturase(SCD) mRNA concentrations of
subcutaneous adipose tissue in sheep
Plt0.001
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Effect of feeding forage or concentrate-based
diets on fatty acid composition of subucateous
adipose tissue in sheep
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PROTECT FAT FROM RUMEN

• Coat the fat so that it escapes the action of the
  rumen bacteria
• The coat is then broken down in either abomasum
  or the duodenum

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Effect of feeding rumen- protected fish oil on
the muscle fatty acid content of lot-fed
cattleAshes et al (2000) Recent Advances in
Animal Nutrition, 129-140
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Trans-10, cis 12-CLA
Cis- 9, trans 11-CLA
Linoleic acid
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Why interested in CLAs?Suggested health benefits
to humans

• Altered nutrient partitioning and lipid
  metabolism
• Antiatherogenic
• Anticarcinogenic
• Antidiabetic (type II diabetes)
• Immunity enhancement
• Improved bone mineralization

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Production of CLAs in the rumen
Linoleic Acid cis-9, cis-12 182
cis-9, trans-11 CLA
trans-10, cis-12 CLA
trans-11 181
trans-10 181
Stearic acid
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Production of CLA
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Effect of feeding forage or concentrate-based
diets on the CLA content of abomassal fluid,
subcutaneous adipose tissue L. dorsi muscle of
sheep
cis 9, trans 11
trans 10, cis 12
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Seasonal variation in cis 9, trans 11-CLA content
of milk
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SCD ACTIVITY

• There is some evidence that there is genetic
  variation
• Some cows seems to produce more CLA in the diet
  than others.Polymorphisms in the SCD gene?
• We have not been able to find much variation in
  adipose tissue and liver of sheep

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Production of CLA-enriched butterIp et al (1999)
J Nutr 129 2135-2142
Cows fed 5.3 sunflower oil and selected for CLA
production
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Effect of CLA on development of Mammary Cancer in
rats
30 rats per group were treated with a chemical
carcinogen. Values represent the number of
animals with tumours adapted from Ip et al (1999)
J. Nutr 1292135-2142 primarily cis-9, trans-10
isomer
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Could it be used in humans?

• Rats were fed 20 (w/w) butter
• Rats weighed 180g and would probably consume
  about 10g of food a day (2g) butter
• This is equivalent to 11g butter/kg body
  weight/day
• Thus a 70kg man would have to consume 770g
  butter/day to get the same amount
• More research is needed
• Professor Bauman in the USA working in the area

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Manipulating supply of CLA to sheep tissues

• Rumen saturates fatty acids therefore need to
  protect CLA supplement (containing equal levels
  c-9,t-11 and t-10,c-12) from ruminal degradation
  to ? absorption in small intestine

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Rumen protected CLA
Proportion of ingested CLA reaching Duodenum
CLA-80 protected by Trouw Nutrition Used matrix
of saturated fat of vegetable origin and final
product produced by prilling, spray drying and
spray chilling. Determined to be 70
protected in cannulated sheep by dual-phase
markers
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How much do we feed?

• Ostrowska et al., (1999)
• Growing pigs fed CLA-55 (mixture of both isomers)
• 0, 1.25, 2.5, 5, 7.5, 10g CLA/kg diet
• Fat deposition decreased with increasing CLA
• Fatlean decreased with increasing CLA
• Av 80 kg pig _at_ highest dose 0.19 g CLA/kg body
  weight/day

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How much do we feed?

• PCLA 66 effective at bypassing rumen
  biohydrogenation
• High levels lipid adversely affect rumen function
• Max amount PCLA supplied daily to small intestine
  of av. 40 kg lamb calculated 0.28 kg CLA/kg BW
• Predicted that lambs would consume 1 kg DM/day
  therefore highest PCLA inclusion was 100 g/kg DM
• 25 and 50g/kg DM groups for dose response

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Trial Outline

• 36 ewe lambs Inclusion g/kg feed
  GE/day (MJ)
• Control (n6) 18.42
• Low PCLA (n5) 25 19.42
• Med PCLA (n5) 50 19.86
• Hi PCLA (n5) 100 21.30
• Low Megalac (n5) 21.7 19.14
• Med Megalac (n5) 43.3 19.86
• Hi Megalac (n5) 86.6 21.30
• Megalac controls for lipid coating of PCLA
• Fed for 10 wks, control group designed to grow at
  180 g/d

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Sample analysis

• Fatty acid composition
• Did the CLA get into the animals tissues?
• Carcass characteristics
• Repartitioning effects of CLA?

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Subcutaneous CLA content
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Omental CLA content
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Perirenal CLA content
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L. dorsi CLA content
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Liver CLA content
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Effect of dietary CLA on carcass fat
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Carcass characteristics

• No change in carcass composition
• Carcass cold weight
• Back fat thickness
• Omental and perirenal depot whole weights
• Muscle weight (L. Dorsi, V. Lateralis, S.
  Tendenosus)
• Eye muscle depth or width
• Liver weight
• BUT definite incorporation of CLA into tissues

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Accumulation of CLA(t10,c12) in subcutaneous
adipose tissue
Pig data adapted from Ostrowska et al (2003)
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Effect of dietary CLA on carcass fat
PIGS
SHEEP
Adapted from Ostrowska et al (2003)
Corrected for protection
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Conclusion

• Tissue CLA content increased but no effect on
  carcass
• Maybe ruminant adipose tissue responds
  differently to monogastrics?

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Conclusions

• Animal products continue to supply a major
  proportion of dietary saturated fatty acids
• SCD plays a major role in determining the nature
  of fatty acids synthesized in tissues
• It is possible to increase the concentration of
  healthy fatty acids (e.g. n-3 PUFA CLA) in
  meat dairy produce but whether the changes can
  be great enough to have a significant impact on
  human health remains to be established

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Acknowledgement

• Professor Andrew Salter
• Dr Sean Richards
• Dr Zoe Daniel
• Dr Richard Wynn