Benefits of Grass-fed Benefits of Grass-fed BeefBeef

Susan DuckettErnest L. Corley, Jr. Trustees Endowed Chair

Department of Animal and Veterinary SciencesClemson University

OutlineOutline Fat and CholesterolFat and Cholesterol

Good, bad, and neutral fatsGood, bad, and neutral fats Grass-fed vs. Grain-fed BeefGrass-fed vs. Grain-fed Beef

Results from Appalachia Beef Project (2002-2004)Results from Appalachia Beef Project (2002-2004) Comparison to Chicken and SalmonComparison to Chicken and Salmon

Forage Species for finishingForage Species for finishing Results from Appalachia Beef Project (2005-2007)Results from Appalachia Beef Project (2005-2007) Results from Clemson SARE Project (2007-2008)Results from Clemson SARE Project (2007-2008)

Animal Age and TendernessAnimal Age and Tenderness Results from Appalachia Beef Project (2008)Results from Appalachia Beef Project (2008)

Dietary Fat and Dietary Fat and CholesterolCholesterol

0

100

200

300

400

500

600

700

x 100

0

Heart Disease Cancer Stroke

Chronic respiratory Accidents Diabetes

Alzheimer's Influenza

Heart Disease – #1 Cause of Death in US

Dietary Cholesterol Dietary Cholesterol IntakeIntake

Two Sources of cholesterolTwo Sources of cholesterol Diet – 25%Diet – 25% Body (endogenous synthesis) – 75%Body (endogenous synthesis) – 75%

150 mg reduction150 mg reduction in dietary in dietary cholesterolcholesterol Reduce from average (450 mg/d) to AHA Reduce from average (450 mg/d) to AHA

recommended levels (300 mg/d)recommended levels (300 mg/d) Reduce blood cholesterol about 2%Reduce blood cholesterol about 2%

StatinsStatins (i.e. Lipitor, Zocor, etc.) (i.e. Lipitor, Zocor, etc.) Lower cholesterol synthesis in liverLower cholesterol synthesis in liver Reduce blood cholesterol levels about 40-Reduce blood cholesterol levels about 40-

60%60%

Results from Pasture Results from Pasture Based Beef Based Beef

Systems for AppalachiaSystems for Appalachia

Multi-State, Multi-Multi-State, Multi-Institutional Research Institutional Research

CollaborationCollaboration

Pasture Based Beef Systems for Pasture Based Beef Systems for AppalachiaAppalachia

In 2002, 2003, and 2004, 216 Angus-cross In 2002, 2003, and 2004, 216 Angus-cross steers steers

42-d backgrounding period after weaning - VT42-d backgrounding period after weaning - VT Winter Stocker System – WVU (Nov. – April)Winter Stocker System – WVU (Nov. – April)

Low (0.55 lb/d), Medium (1.10 lb/d), High (1.65 Low (0.55 lb/d), Medium (1.10 lb/d), High (1.65 lb/d) growth rateslb/d) growth rates

Finishing System (April – October)Finishing System (April – October) Concentrate (Concentrate (GRAINGRAIN) – Corn grain/corn silage diet ) – Corn grain/corn silage diet

at VTat VT Pasture (Pasture (GRASSGRASS) – high quality forage at all times ) – high quality forage at all times

in Beaver, WV in Beaver, WV Harvested at Taylor-Excel in PA, carcass data Harvested at Taylor-Excel in PA, carcass data

collectedcollected Whole rib from each carcass obtained for meat Whole rib from each carcass obtained for meat

quality analysesquality analyses

Cholesterol Content of Meat

Animal products contain cholesterol. Cholesterol is present in all cell membranes

including muscle and fat.

No difference in cholesterol content of grass vs. grain-fed beef

Fat and Serum Fat and Serum CholesterolCholesterol Most Important:Most Important:

Type and amount of fat consumedType and amount of fat consumed Why:Why:

Influences lipoproteins (LDL or HDL) Influences lipoproteins (LDL or HDL) LDL-cholesterolLDL-cholesterol or or BADBAD cholesterol cholesterol

Carries cholesterol from liver to tissuesCarries cholesterol from liver to tissues Excess builds up in arteries (plaques)Excess builds up in arteries (plaques)

HDL-cholesterolHDL-cholesterol or or GOODGOOD cholesterol cholesterol Removes cholesterol from blood back to liver Removes cholesterol from blood back to liver

for elimination from bodyfor elimination from body NCEP: NCEP:

> 40 mg/dL HDL > 40 mg/dL HDL < 100 mg/dL LDL< 100 mg/dL LDL

HeartHeart Disease Disease

Fatty Acid TypesFatty Acid Types

Saturated, SFA (Stearic acid, 18C)

C1-C2-C3-C4-C5-C6-C7-C8-C9-C10-C11-C12-C13-C14-C15-C16-C17-C18OOH

Monounsaturated, MUFA (Oleic acid, 18C)

C1-C2-C3-C4-C5-C6-C7-C8-C9=C10-C11-C12-C13-C14-C15-C16-C17-C18OOH

Omega-6 polyunsaturated, PUFA-6 (Linoleic acid, 18C)

C1-C2-C3-C4-C5-C6=C7-C8-C9=C10-C11-C12-C13-C14-C15-C16-C17-C18OOH

Omega-3 polyunsaturated, PUFA-3 (Linolenic acid, 18C)

C1-C2-C3=C4-C5-C6=C7-C8-C9=C10-C11-C12-C13-C14-C15-C16-C17-C18OOH

= denotes double bond location

Fat and Serum Fat and Serum CholesterolCholesterol

Not all saturated fats (SFA) are Not all saturated fats (SFA) are created equalcreated equal

Bad SFABad SFA Increase LDL (Bad) cholesterolIncrease LDL (Bad) cholesterol Myristic (C14:0) and Palmitic (C16:0) Myristic (C14:0) and Palmitic (C16:0)

acidsacids Okay SFA Okay SFA

No change in LDL or HDL CholesterolNo change in LDL or HDL Cholesterol Stearic (C18:0) acidStearic (C18:0) acid

Saturated Fatty Acids Saturated Fatty Acids (SFA)(SFA)

Greater concentrations of okay SFA (Stearic acid) and lower concentrations of Bad SFA (myristic

and palmitic acids) in grass-fed beef

Fat and Serum Fat and Serum CholesterolCholesterol

Good MUFAGood MUFA (1 double bond) (1 double bond) Oleic (C18:1) acid – major fatty acid in beef (30-Oleic (C18:1) acid – major fatty acid in beef (30-

50%)50%) Lowers bad (LDL) and increases good (HDL) Lowers bad (LDL) and increases good (HDL)

cholesterolcholesterol Good PUFAGood PUFA (2 or more double bonds) (2 or more double bonds)

PUFA-6PUFA-6 Linoleic (C18:2) and arachidonic (C20:4) acidLinoleic (C18:2) and arachidonic (C20:4) acid Lower bad (LDL) and tend to lower good (HDL) Lower bad (LDL) and tend to lower good (HDL)

cholesterolcholesterol PUFA-3PUFA-3

Linolenic acid (C18:3), EPA (C20:5), DPA (C22:5), DHA Linolenic acid (C18:3), EPA (C20:5), DPA (C22:5), DHA (C22:6)(C22:6)

Lower bad (LDL) cholesterolLower bad (LDL) cholesterol Reduce risk of heart disease, stroke and cancerReduce risk of heart disease, stroke and cancer

Monounsaturated fatty acid (MUFA)

25.0

27.5

30.0

32.5

35.0

37.5

40.0

42.5

45.0

MU

FA

, % Grain-fedGrass-fed

Lower levels of Good MUFA fat for Grass-fed

Polyunsaturated fatty acid

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

%

Grain-fedGrass-fed

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

Greater percentages of Good PUFA-3 fat for Grass-fed

PUFA-6 PUFA-3

Cancer Fighting Cancer Fighting CompoundsCompounds

In ruminant animals, dietary PUFA are biohydrogenated in rumen

Produces intermediates that have anticarcinogenic properties: Conjugated linoleic acid (CLA), cis-9

trans-11 isomer Trans-11 Vaccenic acid (TVA)

In beef and milk, over 86% of CLA present in these animal products comes from desaturation of TVA

In humans, 19% of supplemented TVA was converted to CLA (range 0 - 40%)

Conjugated Linoleic Acid (CLA)

Grass vs. Grain: 9.4-fold greater TVA and 1.2-fold greater CLA

Total Fat per serving: Beef vs. Total Fat per serving: Beef vs. OthersOthers

Grass vs. Grain: 46% reduction in total fat content

BAD SFA: Beef vs. OthersBAD SFA: Beef vs. Others

Grass vs. Grain: 53% reduction in bad saturated fat content

PUFA 3: Beef vs. OthersPUFA 3: Beef vs. Others

Omega-6 to Omega-3 Omega-6 to Omega-3 RatioRatio

Health professionals recommend ratio of 4:1 or less

Changes in American Changes in American DietDiet

Increased intake of omega-6 and trans fat

Omega-3Omega-3 Levels Levels Health professionals recommend diets with Health professionals recommend diets with

ratio of less than 4:1ratio of less than 4:1 Lyon Heart StudyLyon Heart Study

Dietary intervention study in patients after 1Dietary intervention study in patients after 1stst myocardial infraction; reduced linoleic to linolenic myocardial infraction; reduced linoleic to linolenic ratio to 4:1ratio to 4:1

76% decrease in mortality after 2 yrs on intervention 76% decrease in mortality after 2 yrs on intervention dietdiet

Source of omega-3, Australian dietSource of omega-3, Australian diet Red meat supplied over 70% of total dietary DPARed meat supplied over 70% of total dietary DPA

2 servings/d of grass-fed beef vs. grain-fed2 servings/d of grass-fed beef vs. grain-fed +11 g/yr omega-3 fatty acids+11 g/yr omega-3 fatty acids -1460 g/yr of total fat-1460 g/yr of total fat

Cancer-Fighting Cancer-Fighting CompoundsCompounds

19% to CLA

VitaminsVitamins

Antioxidants B-vitamins

Warner-Bratzler Shear Force

Forage Species; WVForage Species; WV

Mixed: Bluegrass/White Clover

Mixed Alfalfa Pearl Millet

First 93 d

Final 41 d

128 Angus-cross steers, 3 yr. study

abMeans with uncommon superscripts differ (P < 0.05)

Carcass Weight

abMeans with uncommon superscripts differ (P < 0.05)

Total Lipid ContentTotal Lipid Content

b b b

a

Monounsaturated fatty acidsMonounsaturated fatty acids

a

PUFA-6 and PUFA-3PUFA-6 and PUFA-3

Ratio of Omega-6:Omega-3

b b b

a

Cancer Fighting Cancer Fighting CompoundsCompounds

a

aaa

b

Warner-Bratzler Shear Warner-Bratzler Shear ForceForce

Descriptive Flavor PanelDescriptive Flavor PanelFlavor Mean Intensity TablesFlavor Mean Intensity Tables11

TreatmentA 10.30 b 11.61 a 0.12 b 2.98 a 2.98 a

F 11.12 a 11.68 a 0.07 b 2.94 a 2.94 a

N 9.99 b 11.61 a 0.31 a 2.85 a 2.85 a

PM 10.38 b 11.65 a 0.08 b 2.91 a 2.91 a

P-value 0.00 0.97 0.01 0.01 0.45

MetallicBeef Flavor

IDBrown

Roasted Organ MeatBloody/Serumy

TreatmentA 0.13 a 0.71 a 2.11 a 1.64 a 2.68 ab

F 0.08 a 0.18 b 2.01 b 1.77 a 2.54 b

N 0.13 a 0.77 a 2.14 a 1.63 a 2.74 a

PM 0.13 a 0.57 ab 2.10 ab 1.62 a 2.67 ab

P-value 0.93 0.02 0.05 0.36 0.20

Sour Salty BitterRancid Off-Note

1 a, b Means with the same letter within a column are not significantly different at the 95% Confidence Level 1 Means based on 15-point scale with 0.5-increments. 0.0 = none -- 15.0 = extreme

A = Alfalfa; F = Concentrate, C; N = Mixed pasture, MP; PM = Pearl Millet

Forage Species Alters Animal Forage Species Alters Animal Performance, Performance,

Carcass Quality, and Fatty Acid Carcass Quality, and Fatty Acid Composition of Composition of

Forage-Finished Beef Produced in Forage-Finished Beef Produced in Summer Months Summer Months

J. Schmidt, J. Andrae, S. Duckett, M. Miller, S. J. Schmidt, J. Andrae, S. Duckett, M. Miller, S. EllisEllis

Clemson University, Clemson, SCClemson University, Clemson, SC

Forage Species for Summer Forage Species for Summer FinishingFinishing

Alfalfa (Alfalfa (Medicago sativaMedicago sativa) – ) – perennial legumeperennial legume September establishment with a seeding rate of 20 kg haSeptember establishment with a seeding rate of 20 kg ha-1-1

Bermudagrass (Bermudagrass (Cynodon dactylonCynodon dactylon) – ) – warm season warm season perennial grassperennial grass

Existing paddocks (c.v. ‘Coastal’) were utilizedExisting paddocks (c.v. ‘Coastal’) were utilized

Chicory (Chicory (Cichorium intybusCichorium intybus) – ) – short-lived perennial forbshort-lived perennial forb September establishment with a seeding rate of 9 kg haSeptember establishment with a seeding rate of 9 kg ha-1-1

Cowpea (Cowpea (Vigna unguiculataVigna unguiculata) – ) – warm season annual warm season annual legumelegume

May establishment with a seeding rate of 56 kg haMay establishment with a seeding rate of 56 kg ha-1-1

Pearl Millet (Pearl Millet (Pennisetum glaucumPennisetum glaucum) – ) – warm season warm season annual grassannual grass

May establishment with a seeding rate of 28 kg haMay establishment with a seeding rate of 28 kg ha-1-1

Materials & MethodsMaterials & Methods 30 Angus-cross steers 30 Angus-cross steers 2-ha paddocks; 2-reps per forage species 2-ha paddocks; 2-reps per forage species Grazing began when adequate forage growth was Grazing began when adequate forage growth was

presentpresent alfalfa & chicory: April - Julyalfalfa & chicory: April - July bermudagrass, cowpea & pearl millet: June – Sept./Oct.bermudagrass, cowpea & pearl millet: June – Sept./Oct.

Alternate stocking was utilized to provide forage Alternate stocking was utilized to provide forage rest periodrest period

Put and take stocking was utilized to maintain Put and take stocking was utilized to maintain recommended herbage allowancerecommended herbage allowance

Slaughtered when forage mass inadequate or live Slaughtered when forage mass inadequate or live weight exceeded 568 kgweight exceeded 568 kg

Carcass data collected at 48 h postmortemCarcass data collected at 48 h postmortem

Hot Carcass WeightHot Carcass Weight

Carcass Quality ResultsCarcass Quality Results

AL BG CH CO PM

Fat Thickness, in

.31c .21d .22cd .29c .18d

Dressing % 63.4a 59.2b 63.0a 63.2a 60.5b

Ribeye Area, in2

13.1 12.9 12.4 12.7 12.2

Yield Grade 2.2 2.0 2.1 2.4 1.9

Quality Grade1

4.17ab 3.83ab 3.67b 4.83a 3.23b

1Quality Grade: 3 = Low Select, 4 = High Select, 5 = Choice- a,bMeans with uncommon superscripts in the same row

differ (P<0.05)c,dMeans with uncommon superscripts in the same row

differ (P<0.1)

Warner-Bratzler Shear Warner-Bratzler Shear ForceForce

Shear Force, d 14Shear Force, d 14

Consumer PanelConsumer Panel

Monounsaturated Fatty Acids

MUFA: AL and PM > CH

Cancer-Fighting Cancer-Fighting CompoundsCompounds

Grasses (BG and PM): higher Vaccenic and CLA levels

Animal AgeAnimal Age Medium or Large frame sires; 3 time Medium or Large frame sires; 3 time

endpoints endpoints (1=July 17, 2=Sept. 3, 3=Oct. 30, 2008)(1=July 17, 2=Sept. 3, 3=Oct. 30, 2008)

Animal age and Postmortem Aging Time – Critical for Beef Tenderness

SummarySummary Grass-fed beefGrass-fed beef

Leaner with low n-6 to n-3 ratioLeaner with low n-6 to n-3 ratio Greater concentrations of n-3, CLA and Greater concentrations of n-3, CLA and

vaccenicvaccenic Greater antioxidant and B-vitamin contentsGreater antioxidant and B-vitamin contents Tender and tastes greatTender and tastes great

Forage speciesForage species Alter animal performance, carcass quality, Alter animal performance, carcass quality,

tenderness, fatty acid composition, and flavortenderness, fatty acid composition, and flavor Develop forage chains to expand finishing Develop forage chains to expand finishing

windowwindow Animal age and tendernessAnimal age and tenderness

Young = tender Young = tender Greater animal age – increased postmortem Greater animal age – increased postmortem

agingaging

Supplementation on Forage

0.0

0.5

1.0

1.5

2.0

2.5

3.0

Trans-11 vaccenic CLA

% o

f to

tal f

atty

aci

ds

Forage onlyForage + GrainConcentrate

Corn Grain: Reduced TVA and CLA compared to Forage only but values greater than Concentrate

Supplementation on Forage

0

1

2

3

4

5

6

Rat

io o

f O

meg

a6:O

meg

a3

ForageForage + OilForage + GrainConcentrate

Oil and Grain Supplementation: Increased omega-6:Omega-3 ratio due to greater intake of omega-6 fat

Subcutaneous Fat Color

0

2

4

6

8

10

12

14

16

18

20

b*

MixedAlfalfaPearl MilletConcentrate

b

a a a

S.C. b* Distribution

Treatments1=AL, 2=C, 3=MP, 4=PM

1 2 3 4

S.C

. b*

10

12

14

16

18

20

22

24