BEEF QUALITY:BEEF QUALITY:WHAT IS IT? — HOW TO WHAT IS IT? — HOW TO

PRODUCE ITPRODUCE IT

Harlan RitchieDepartment of Animal Science

Michigan State UniversityEast Lansing, Michigan 48824

WHAT IS BEEF QUALITY?WHAT IS BEEF QUALITY?

In fresh, uncooked beef, it is:

Color of the muscle

Amount of fat

Subcutaneous fat (external fat; on border of muscles)

Intermuscular fat (seam fat; between muscles)

Intramuscular fat (marbling; within the muscle)

Color of the fat (white vs. yellow)

NORMAL AND DARK-CUTTING BEEFNORMAL AND DARK-CUTTING BEEF

Dikeman, 1993

CONSUMERS’ VISUAL PREFERENCE FOR CONSUMERS’ VISUAL PREFERENCE FOR NORMAL- VS. DARK-COLORED FRESH BEEF NORMAL- VS. DARK-COLORED FRESH BEEF

STEAKS STEAKS aa

Consumers were asked to visually evaluate fresh strip loin steaks that differed in color: dark vs. normal (bright cherry-red).

Sixty-eight percent of the participants preferred normal color and were willing to pay a premium of $0.23 per kg ($1.69 vs. $1.46).

a Calkins et al. 2000. J. Anim. Sci. 78 (Suppl. 1):23.

PRE-HARVEST STRESS AND DARK PRE-HARVEST STRESS AND DARK CUTTNG BEEF CUTTNG BEEF aa

Factors that affect the occurrence of dark cutting beef are:

Gender (heifers are more excitable than steers) Stressful cattle handling procedures Mixing cattle from different pens or locations Long transportation and holding times Large fluctuations in temperature prior to

harvesta Scanga et al. 1998. J. Anim. Sci. 76:2040.

WHAT IS BEEF QUALITY?WHAT IS BEEF QUALITY?

In cooked beef, it is:

Flavor

Juiciness

Tenderness

PALATABILITY OF COOKED BEEFPALATABILITY OF COOKED BEEF

Palatability of cooked beef is determined by the combined effects of flavor, juiciness, and tenderness. Flavor intensity is related to the amount of intramuscular fat

(marbling), and the compounds that arise from muscle changes during postmortem aging.

Juiciness is determined by amounts of intramuscular moisture and marbling that remain in the muscle after cooking.

Tenderness is determined by extent of postmortem muscle fiber shortening and breakdown, and the amounts of moisture, marbling, and intact connective tissue left after cooking.

CONSUMERS’ PERCEPTION OF THE CONSUMERS’ PERCEPTION OF THE IMPORTANCE OF SENSORY IMPORTANCE OF SENSORY

ATTRIBUTESATTRIBUTES

0

10

20

30

40

50

Tenderness Flavor Juiciness

Miller et al., 1995

Fre

qu

ency

, %

CONSUMER PURCHASE PREFERENCE OF STEAKS CONSUMER PURCHASE PREFERENCE OF STEAKS VARYING IN TENDERNESS WHEN PRICED ACCORDINGLYVARYING IN TENDERNESS WHEN PRICED ACCORDINGLY

1.8 %3.6 %

94.6 %

0

10

20

30

40

50

60

70

80

90

100

Boleman et al., 1995

Red(Tender)$4.34/lb

White(Intermediate)

$3.84/lb

Blue(Tough)$3.34/lb

Pu

rch

as

e p

refe

ren

ce

, %

TENDERNESSTENDERNESS

PRE-HARVEST FACTORS THAT AFFECT PRE-HARVEST FACTORS THAT AFFECT BEEF TENDERNESSBEEF TENDERNESS

1. Muscle location and function2. Muscle fiber type and size3. Breed4. Gender5. Time on grain feeding6. Age at harvest7. Disease8. Intramuscular injection site lesions9. Feeding high levels of vitamin D prior to slaughter

10. Preharvest stress11. Animal temperament12. USDA quality grade (marbling)13. Genetic selection for tenderness

BREEDSBREEDS

Research has shown that British breeds are more tender than Continental breeds and Bos indicus breeds are less tender than either Continental or British breeds.

In commercial crossbreeding programs, acceptable tenderness can usually be achieved by marketing progeny that have:

A minimum of 1/2 British breeding A maximum of 1/4 to 3/8 Bos indicus breeding

0

1

2

3

4

5

6

7

8

9

0 50 100 150 200

Days on Feed

Sh

ear

Fo

rce

(Kg

)

(From May et al., 1992)

EFFECT OF AGE ON BEEF EFFECT OF AGE ON BEEF TENDERNESSTENDERNESS

When harvested at an equal fat thickness endpoint within an age range of 9 to 30 months, there is a tendency for younger cattle to be more tender than older cattle

As cattle advance in age beyond 30 months, tenderness declines rapidly, because of increasing amounts of connective tissue.

EFFECT OF RESPIRATORY DISEASE EFFECT OF RESPIRATORY DISEASE ON BEEF QUALITY ON BEEF QUALITY aa

Steers having no lung lesions showed the following advantages over those having lung lesions due to respiratory disease:

Significantly higher marbling scores and USDA quality grades

Significantly improved shear force (tenderness) values

a Gardner et al. 1998. Oklahoma State Univ. Research Report.

EFFECT OF INJECTION SITE LESIONS ON EFFECT OF INJECTION SITE LESIONS ON BEEF TENDERNESSBEEF TENDERNESS

Intramuscular injection of various biological and pharmaceutical compounds into the outside round and top sirloin butt resulted in significantly less tender (P < .001) steaks from these muscles.

The toughened area covered a radius of 3 inches (7.6 cm) from the center of the injection site lesion.

Trimming of the affected tissue represented a loss of nearly $6 per animal.

SOURCE: Colorado State Univ. Beef Program Reports (1993, 1995, 1996, 1997, 1999)

EFFECT OF TEMPERAMENT ON ANIMAL EFFECT OF TEMPERAMENT ON ANIMAL WEIGHT GAIN AND BEEF QUALITYWEIGHT GAIN AND BEEF QUALITY

Colorado State University researchers scored 531 feedlot cattle for temperament (1=calm; 5=extremely excitable). As temperament scores increased:

There was a highly significant (P < .001) decrease in average daily gain.

There was a significant (P < .01) increase in the incidence of dark cutting beef.

There was a highly significant (P < .001) decrease in meat tenderness as evaluated by shear force.

SOURCE: Voisinet et al. 1997. Meat Science 46(4):367

HOW IMPORTANT IS HOW IMPORTANT IS

MARBLING MARBLING

(INTRAMUSCULAR FAT)?(INTRAMUSCULAR FAT)?

WHAT IS THE ROLE OF MARBLING?WHAT IS THE ROLE OF MARBLING?

Research has shown that marbling accounts for only about 10% of the variation in beef tenderness.

However, recent studies show that some consumers credit higher-marbled beef with being significantly more tender than it really is:

It appears that these consumers prefer the flavor of higher-marbled beef above and beyond any tenderness that exists.

Therefore, it could be very important to identify those consumers who prefer high-marbling flavor vs. those who prefer low-marbling flavor.

RELATIONSHIP BETWEEN QUALITY GRADE AND RELATIONSHIP BETWEEN QUALITY GRADE AND TENDERNESS OF RETAIL STRIP LOIN STEAKS TENDERNESS OF RETAIL STRIP LOIN STEAKS

(Sensory Evaluation Panel)(Sensory Evaluation Panel)

Qualitygrade

Odds ofobtaining atough steak

Prime 0

Upper 2/3 of Choice 1 in 10

Low Choice 1 in 5

Select 1 in 4

SOURCE: George et al. 1999. J. Anim. Sci. 77:1735

RELATIONSHIP BETWEEN QUALITY GRADE RELATIONSHIP BETWEEN QUALITY GRADE AND TENDERNESS OF RETAIL LOIN STEAKSAND TENDERNESS OF RETAIL LOIN STEAKS

“Quality grades were reasonably effective for categorizing retail loin steaks according to differences in tenderness when quality grade ranged from Select to Prime, but were not effective for identifying tenderness differences between Select and Low Choice steaks (the narrow range in which over 80% of U.S. fed beef is graded).”

SOURCE: George et al. 1999. J. Anim Sci. 77:1735

AVERAGE HERITABILITY ESTIMATES FOR AVERAGE HERITABILITY ESTIMATES FOR CARCASS TRAITS (AGE-CONSTANT) CARCASS TRAITS (AGE-CONSTANT) aa

TraitAverage

heritability

Market weight .41

Carcass weight .23

Dressing percent .39

Backfat thickness .44

Ribeye area .42

Cutability (retail product %) .47

Lean percentage .55

Marbling score .38

Warner-Bratzler shear force .29a Koots et al. (1994); summary of 287 global studies covering 45

years (1946 to 1991).

POTENTIAL CORRELATED RESPONSESPOTENTIAL CORRELATED RESPONSESTO SELECTION FOR MARBLINGTO SELECTION FOR MARBLING

Favorable: Decreased shear force (.39) Increased preweaning gain (.39)

Unfavorable: Increased fat thickness (.37) Decreased ribeye area (.14) Decreased % retail product (.24)

SOURCE:D.M. Marshall (1994); genetic correlations are in parentheses

BEEF QUALITY OF HEREFORD AND HEREFORD BEEF QUALITY OF HEREFORD AND HEREFORD CROSS CATTLE VS. USDA CHOICE AND SELECT CROSS CATTLE VS. USDA CHOICE AND SELECT

GRADE CARCASSESGRADE CARCASSES

An extensive study involving 1,000 Hereford and Hereford cross steers and heifers, 120 USDA Choice, and 120 USDA Select grade carcasses gave the following results: Hereford and Hereford cross carcasses quality graded 38% USDA

Choice and 56% USDA Select.

Hereford and Hereford crosses were equal to USDA Choice beef in tenderness ratings and superior to USDA Select.

Hereford and Hereford crosses were superior in overall palatability ratings to both USDA Choice and Select.

SOURCE: Huffines (1992).

POSTWEANING EFFICIENCY AT VARIOUS MARKET ENDPOINTS POSTWEANING EFFICIENCY AT VARIOUS MARKET ENDPOINTS (MARC)(MARC)

Market endpoint

Breed groupTime,207 d

Gain,507 lb

Carcassweight,734 lb

Retailproduct,

463 lb

Marblingscore,Small0

Ribeyefat, 4%

Grams live weight gain/Mcal of metabolizable energy

Red Poll 49 48 48 47 51 52Hereford 54 48 51 46 57 61Angus 50 48 49 46 54 57Limousin 54 51 54 57 47 41Braunvieh 50 51 51 51 49 48Pinzgauer 50 50 50 50 51 51Gelbvieh 48 49 49 50 45 43Simmental 51 52 52 54 49 48Charolais 52 52 53 55 49 46Diff. (P < .05)a 1.9 2.5 2.0 2.4 1.9 2.3

a Difference (P < .05) is the approximate difference between means of breeds required for statistical significance.

CAN WE DIRECTLY CAN WE DIRECTLY

MEASURE TENDERNESS IN MEASURE TENDERNESS IN

FRESH BEEF?FRESH BEEF?

INSTRUMENTATION TO EVALUATE INSTRUMENTATION TO EVALUATE BEEF PALATABILITYBEEF PALATABILITY

Swatland connective tissue probe

MARC Tenderness Classification System

Colorimeter System

NIR (Near-Infrared Spectroscopy)

Denver Research Institute Ultrasound System

HunterLab BeefCam™

HUNTERLAB BEEFCAM™HUNTERLAB BEEFCAM™SYSTEM FOR EVALUATINGSYSTEM FOR EVALUATING

BEEF PALATABILITYBEEF PALATABILITY

Of those carcasses certified as tender using the BeefCam™ system:

98.6% were found to be tender by shear force evaluation

79.7% were rated as tender by a trained taste panel

SOURCE: Belk (1999)

““BeefCam technology is the BeefCam technology is the

most promising non-invasive most promising non-invasive

technique ever identified for technique ever identified for

use in predicting palatability of use in predicting palatability of

cooked beef from cooked beef from

measurements taken on the measurements taken on the

raw carcass.”raw carcass.”

G.C. Smith Colorado State Univ.

GENETIC SELECTION FOR GENETIC SELECTION FOR

BEEF CARCASS TRAITSBEEF CARCASS TRAITS

EFFECTIVENESS OF STRATEGIES TO EFFECTIVENESS OF STRATEGIES TO IMPROVE TENDERNESS IMPROVE TENDERNESS aa

Strategy

% strip loinsteaks unacceptable

in tenderness

3 days postmortem aging 64%

21 days postmortem aging 28%

21 days aging + high voltage E.S. 22%

Aging + E.S. + 25% of least tender sires culled 12%

Aging + E.S. + 25% of most tender sires kept 1%

a Tatum et al. 1997. Final Report to NCBA.

THE FUTURETHE FUTURE

EPDs/EBVs (Estimated Breeding Values) for tenderness will be available.

Major genes for tenderness and other carcass traits will be identified.

DNA testing of live cattle for carcass traits will be developed.

Increased emphasis on muscling because of its impact on red meat yield.

Multiple-trait selection technology will combine carcass, reproduction, and growth traits into a single profit index that can be tailored to the objectives of individual cattle breeders.

THE FUTURETHE FUTURE

“I prefer the dreams of the future to the history of the past.”

Thomas Jefferson

THE FUTURETHE FUTURE

“Our real task is not to foresee the future, but to enable it.”

Saint Exupery in Wisdom of the Sands

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