Benefits of Grass-fed Beef

1
Benefits of Grass-fed Beef
Susan Duckett Ernest L. Corley, Jr. Trustees
Endowed Chair Department of Animal and Veterinary
Sciences Clemson University
2
Outline

• Fat and Cholesterol
• Good, bad, and neutral fats
• Grass-fed vs. Grain-fed Beef
• Results from Appalachia Beef Project (2002-2004)
• Comparison to Chicken and Salmon
• Forage Species for finishing
• Results from Appalachia Beef Project (2005-2007)
• Results from Clemson SARE Project (2007-2008)
• Animal Age and Tenderness
• Results from Appalachia Beef Project (2008)

3
Dietary Fat and Cholesterol
Heart Disease 1 Cause of Death in US
4
(No Transcript)
5
Dietary Cholesterol Intake

• Two Sources of cholesterol
• Diet 25
• Body (endogenous synthesis) 75
• 150 mg reduction in dietary cholesterol
• Reduce from average (450 mg/d) to AHA recommended
  levels (300 mg/d)
• Reduce blood cholesterol about 2
• Statins (i.e. Lipitor, Zocor, etc.)
• Lower cholesterol synthesis in liver
• Reduce blood cholesterol levels about 40-60

6
Results from Pasture Based Beef Systems for
AppalachiaMulti-State, Multi-Institutional
Research Collaboration
7
Pasture Based Beef Systems for Appalachia

• In 2002, 2003, and 2004, 216 Angus-cross steers
• 42-d backgrounding period after weaning - VT
• Winter Stocker System WVU (Nov. April)
• Low (0.55 lb/d), Medium (1.10 lb/d), High (1.65
  lb/d) growth rates
• Finishing System (April October)
• Concentrate (GRAIN) Corn grain/corn silage diet
  at VT
• Pasture (GRASS) high quality forage at all
  times in Beaver, WV
• Harvested at Taylor-Excel in PA, carcass data
  collected
• Whole rib from each carcass obtained for meat
  quality analyses

8
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
9
Fat and Serum Cholesterol

• Most Important
• Type and amount of fat consumed
• Why
• Influences lipoproteins (LDL or HDL)
• LDL-cholesterol or BAD cholesterol
• Carries cholesterol from liver to tissues
• Excess builds up in arteries (plaques)
• HDL-cholesterol or GOOD cholesterol
• Removes cholesterol from blood back to liver for
  elimination from body
• NCEP
• gt 40 mg/dL HDL
• lt 100 mg/dL LDL

10
Heart Disease
11
Fatty 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-C9C10-C11-C12-C13-C14-C1
5-C16-C17-C18OOH Omega-6 polyunsaturated, PUFA-6
(Linoleic acid, 18C) C1-C2-C3-C4-C5-C6C7-C8-C9C1
0-C11-C12-C13-C14-C15-C16-C17-C18OOH Omega-3
polyunsaturated, PUFA-3 (Linolenic acid, 18C)
C1-C2-C3C4-C5-C6C7-C8-C9C10-C11-C12-C13-C14-C1
5-C16-C17-C18OOH
denotes double bond location
12
Fat and Serum Cholesterol

• Not all saturated fats (SFA) are created equal
• Bad SFA
• Increase LDL (Bad) cholesterol
• Myristic (C140) and Palmitic (C160) acids
• Okay SFA
• No change in LDL or HDL Cholesterol
• Stearic (C180) acid

13
Saturated Fatty Acids (SFA)
Greater concentrations of okay SFA (Stearic acid)
and lower concentrations of Bad SFA (myristic and
palmitic acids) in grass-fed beef
14
Fat and Serum Cholesterol

• Good MUFA (1 double bond)
• Oleic (C181) acid major fatty acid in beef
  (30-50)
• Lowers bad (LDL) and increases good (HDL)
  cholesterol
• Good PUFA (2 or more double bonds)
• PUFA-6
• Linoleic (C182) and arachidonic (C204) acid
• Lower bad (LDL) and tend to lower good (HDL)
  cholesterol
• PUFA-3
• Linolenic acid (C183), EPA (C205), DPA (C225),
  DHA (C226)
• Lower bad (LDL) cholesterol
• Reduce risk of heart disease, stroke and cancer

15
Monounsaturated fatty acid (MUFA)
Lower levels of Good MUFA fat for Grass-fed
16
Polyunsaturated fatty acid
PUFA-6
PUFA-3
Greater percentages of Good PUFA-3 fat for
Grass-fed
17
Cancer Fighting Compounds

• 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)

18
Conjugated Linoleic Acid (CLA)
Grass vs. Grain 9.4-fold greater TVA and
1.2-fold greater CLA
19
Total Fat per serving Beef vs. Others
Grass vs. Grain 46 reduction in total fat
content
20
BAD SFA Beef vs. Others
Grass vs. Grain 53 reduction in bad saturated
fat content
21
PUFA 3 Beef vs. Others
22
Omega-6 to Omega-3 Ratio
Health professionals recommend ratio of 41 or
less
23
Changes in American Diet
Increased intake of omega-6 and trans fat
24
Omega-3 Levels

• Health professionals recommend diets with ratio
  of less than 41
• Lyon Heart Study
• Dietary intervention study in patients after 1st
  myocardial infraction reduced linoleic to
  linolenic ratio to 41
• 76 decrease in mortality after 2 yrs on
  intervention diet
• Source of omega-3, Australian diet
• Red meat supplied over 70 of total dietary DPA
• 2 servings/d of grass-fed beef vs. grain-fed
• 11 g/yr omega-3 fatty acids
• -1460 g/yr of total fat

25
Cancer-Fighting Compounds
19 to CLA
26
Vitamins
Antioxidants
B-vitamins
27
Warner-Bratzler Shear Force
28
Forage Species WV
First 93 d
Mixed Bluegrass/White Clover
Final 41 d
Mixed
Alfalfa
Pearl Millet
128 Angus-cross steers, 3 yr. study
29
Carcass Weight
abMeans with uncommon superscripts differ (P lt
0.05)
abMeans with uncommon superscripts differ (P lt
0.05)
30
Total Lipid Content
a
b
b
b
31
Monounsaturated fatty acids
a
32
PUFA-6 and PUFA-3
33
Ratio of Omega-6Omega-3
a
b
b
b
34
Cancer Fighting Compounds
a
a
a
a
b
35
Warner-Bratzler Shear Force
36
Descriptive Flavor Panel
Flavor Mean Intensity Tables1
A Alfalfa F Concentrate, C N Mixed
pasture, MP PM Pearl Millet

• 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

37
Forage Species Alters Animal Performance,
Carcass Quality, and Fatty Acid Composition of
Forage-Finished Beef Produced in Summer Months
J. Schmidt, J. Andrae, S. Duckett, M. Miller,
S. Ellis Clemson University, Clemson, SC
38
Forage Species for Summer Finishing

• Alfalfa (Medicago sativa) perennial legume
• September establishment with a seeding rate of 20
  kg ha-1
• Bermudagrass (Cynodon dactylon) warm season
  perennial grass
• Existing paddocks (c.v. Coastal) were utilized
• Chicory (Cichorium intybus) short-lived
  perennial forb
• September establishment with a seeding rate of 9
  kg ha-1
• Cowpea (Vigna unguiculata) warm season annual
  legume
• May establishment with a seeding rate of 56 kg
  ha-1
• Pearl Millet (Pennisetum glaucum) warm season
  annual grass
• May establishment with a seeding rate of 28 kg
  ha-1

39
Materials Methods

• 30 Angus-cross steers
• 2-ha paddocks 2-reps per forage species
• Grazing began when adequate forage growth was
  present
• alfalfa chicory April - July
• bermudagrass, cowpea pearl millet June
  Sept./Oct.
• Alternate stocking was utilized to provide forage
  rest period
• Put and take stocking was utilized to maintain
  recommended herbage allowance
• Slaughtered when forage mass inadequate or live
  weight exceeded 568 kg
• Carcass data collected at 48 h postmortem

40
Hot Carcass Weight
41
Carcass 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 (Plt0.05) c,dMeans with
uncommon superscripts in the same row differ
(Plt0.1)
42
Warner-Bratzler Shear Force
43
Shear Force, d 14
44
Consumer Panel
45
Monounsaturated Fatty Acids
MUFA AL and PM gt CH
46
Cancer-Fighting Compounds
Grasses (BG and PM) higher Vaccenic and CLA
levels
47
Animal Age

• Medium or Large frame sires 3 time endpoints
  (1July 17, 2Sept. 3, 3Oct. 30, 2008)

Animal age and Postmortem Aging Time Critical
for Beef Tenderness
48
Summary

• Grass-fed beef
• Leaner with low n-6 to n-3 ratio
• Greater concentrations of n-3, CLA and vaccenic
• Greater antioxidant and B-vitamin contents
• Tender and tastes great
• Forage species
• Alter animal performance, carcass quality,
  tenderness, fatty acid composition, and flavor
• Develop forage chains to expand finishing window
• Animal age and tenderness
• Young tender
• Greater animal age increased postmortem aging

49
(No Transcript)
50
Supplementation on Forage
Corn Grain Reduced TVA and CLA compared to
Forage only but values greater than Concentrate
51
Supplementation on Forage
Oil and Grain Supplementation Increased
omega-6Omega-3 ratio due to greater intake of
omega-6 fat
52
Subcutaneous Fat Color
a
a
53
S.C. b Distribution