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

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”

Dietary Reference Values for Fatty Acids Population averages (% total energy) 1991 Saturated Fatty Acids 10% Cis polyunsaturated fatty acids6% Cis monounsaturated fatty acids12% Trans fatty acids2% Total Fatty Acids30%

Further Recommendations 1994 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)

Saturated fatty acid (SFA) intake in Great Britain target Source: National Food Survey 2000

Contribution of Animal Products to Saturated Fatty Acid (SFA) Intake in Great Britain National Food Survey 2000 Dairy 39% Meat 22% Other 39%

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 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

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 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 Possible Approaches

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

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fat SO diet: 43.5g/kg sunflower oil g/kg rape seed oil RO diet: 75g/kg rape seed oil Budd, Salter, Buttery & Wiseman, unpublished data

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

Adipose Tissue Fatty Acid Deposition in Ruminant Adipose Tissue DIET C18:1/C18:2/C18:3 C18:0 DE NOVO SYNTHESIS C16:0 C18:0 C18:1 Adipose Tissue Rumen

Fatty acid composition abomasal fluid and adipose tissue of sheep fed on grass nuts

Sources of Ruminant Milk Saturated Fatty Acids Acetate/  -OH Butyrate C4:0-C14:0 C16:0 C18:0 Adipose Tissue Diet Mammary Gland C18:1

Comparison of the fatty acid composition of duodenal fluid and milk from cows

Fatty acid synthesis in adipose tissue & mammary gland Acetyl CoA C16:0 C18:0 C18:1 Acetyl CoA C16:0 C18:0 C18:1 Malonyl CA Acetyl CoA Carboxylase (ACC) Fatty Acid Synthase (FAS) Elongase Stearoyl CoA Desaturase (SCD) MAMMARY ADIPOSE

Correlation between SCD mRNA and oleate content of omental adipose tissue of growing sheep

Effect of insulin on SCD gene expression & oleate synthesis in ovine adipose tissue explants cont ins dex ins + dex Ins: 20nM Insulin Dex: 10nM Dexamethosone

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 P<0.001

Effect of feeding forage or concentrate-based diets on fatty acid composition of subucateous adipose tissue in sheep

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

Effect of feeding rumen- protected fish oil on the muscle fatty acid content of lot-fed cattle Ashes et al (2000) Recent Advances in Animal Nutrition,

Trans-10, cis 12-CLA Cis- 9, trans 11-CLA Linoleic acid

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

Production of CLAs in the rumen Linoleic Acid cis-9, cis-12 18:2 cis-9, trans-11 CLA trans-11 18:1 Stearic acid trans-10, cis-12 CLA trans-10 18:1

Production of CLA t11 C18:1 Linoleic acid c9, t11 Stearic acid Rumen t11 C18:1 Adipose tissue c9, t11 Stearic acid SCD Linoleic acid

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

Seasonal variation in cis 9, trans 11- CLA content of milk

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

Production of CLA-enriched butter Ip et al (1999) J Nutr 129: Cows fed 5.3% sunflower oil and selected for CLA production

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 129: primarily cis-9, trans-10 isomer

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

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 Not protected Protected CLA C18:0 CLA

Rumen protected CLA 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 Proportion of ingested CLA reaching Duodenum

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 Fat:lean decreased with increasing CLA Av 80 kg highest dose = 0.19 g CLA/kg body weight/day

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

Trial Outline 36 ewe lambsInclusion g/kg feed GE/day (MJ) 1.Control (n=6) Low PCLA (n=5) Med PCLA (n=5) Hi PCLA (n=5) Low Megalac (n=5) Med Megalac (n=5) Hi Megalac (n=5) Megalac controls for lipid coating of PCLA Fed for 10 wks, control group designed to grow at 180 g/d

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

Subcutaneous CLA content cis-9, trans-11 trans-10, cis-12

Omental CLA content cis-9, trans-11 trans-10, cis-12

Perirenal CLA content cis-9, trans-11 trans-10, cis-12

L. dorsi CLA content cis-9, trans-11 trans-10, cis-12

Liver CLA content cis-9, trans-11 trans-10, cis-12

Effect of dietary CLA on carcass fat

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

Accumulation of CLA(t10,c12) in subcutaneous adipose tissue Pig data: adapted from Ostrowska et al (2003)

Effect of dietary CLA on carcass fat PIGSSHEEP Adapted from Ostrowska et al (2003) *Corrected for protection

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

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

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