Effects of delayed implant protocols on performance,

carcass characteristics and meat tenderness in Holstein steers

J. L. Beckett, and J. Algeo

Cal Poly State University

Algeo Consulting

Strategies

Approximately 20 implants approved for use in cattle

Tremendous number of combinations possible

Producers need to establish strategies that best utilize the advantages of the different implants

Long-fed cattle are particularly subjected to repetitive implant regimens

Effects

Increase frame size– Increases growth curve

Decrease quality grade– Lower % Choice– Due to change in physiological endpoint

Increases muscling Effect on tenderness?

Implant Protocol

No Implant

Ralgro Revalor-S

Revalor-S

Revalor-S

Synovex-C Syn-S

Rev-IS

Rev-ISRevalor-G

0 60 120 180 291

Tre

atm

ent G

roup

s

A

B

C

D

E

Ralgro Syn-S

Revalor-S

Synovex-C

Average Daily Gain

1.2

1.3

1.4

1.5

1.6

1.7

RA/RA/S/Rev C/S/Rev C/IS/Rev G/IS/Rev None

Dai

ly G

ain

(kg)

ab

b b

a

c

Final Weight

500

520

540

560

580

600

620K

ilogr

ams

ab

b b

a

c

Gain to Feed

0.2

0.21

0.22

0.23

0.24

RA/RA/S/Rev C/S/Rev C/IS/Rev G/IS/Rev None

Treatment Group

aa

a a

b

Percentages of Holstein steer carcasses grading USDA Choice or better

57%

51%

39%

27%

53%

0%

10%

20%

30%

40%

50%

60%

70%

Per

cen

t

a

b

ab

a

a

RA/RA/S/Rev C/S/Rev C/IS/Rev G/IS/Rev None

USDA Yield Grade

2.75

2.8

2.85

2.9

2.95

3

3.05

3.1

RA/RA/S/Rev C/S/Rev C/IS/Rev G/IS/Rev None

Treatment Group

Yie

ld G

rad

e

Project Summary

Goal: Identify the time that implants can be initiated to:– Capture maximal growth and performance– Minimize detrimental effects on product

186 steers on feed for 280 d– Initial weight 156 kg

Weighed every 30 daysAt the end of the feeding

phase, animals were harvested and carcass data collected

Diet

Item Starter Ration

Finisher Ration

Starter supplement 15.3 0

Finisher supplement 0 13

Alfalfa 24.16 12

Corn, steam flaked 50 65

Fat, YG 3 4

Cane Molasses 5 6

Soybean meal, 47% CP 2.54 0

Total 100 100

Percent

Average Finishing Ration Analysis

Dry matter 84% Crude Protein 12.79% NEg 1.23 Mcal/kg

NEm 1.95 Mcal/kg

Experimental Protocol

1 2 3 4 5 6

0 - 60 61 - 120 121 - 180 181 - 210 211 - 300 Slaughter

9/10/2000 11/9/2000 1/8/2001 3/9/2001 4/8/2001 6/22/2001

Ralgro Rev-IS Rev-S

Rev-IS Rev-S

Ralgro Ralgro Rev-S

Ralgro Rev-S

None

Treatment

A

E

B

D

C

Days

Tmt period

Interval (days)

480

500

520

540

560

580

600

RA/IS/R

ev

N/IS/R

ev

N/RA/R

A/Rev

N/N/R

A/Rev

None

Kilo

gram

s

a

aa

a

b

Final Weight

Average Daily Gain

1.2

1.3

1.4

1.5

RA/IS/R

ev

N/IS/R

ev

N/RA/R

A/Rev

N/N/R

A/Rev

None

Gai

n/da

y (k

g)

aa

a

a

b

Feed to Gain

0.184

0.186

0.188

0.19

0.192

0.194

0.196

0.198

0.2

RA/IS/Rev N/IS/Rev N/RA/RA/Rev N/N/RA/Rev None

Treatment Group

bc

ab

abc

a

c

Longissimus Muscle Area

64

66

68

70

72

74

76

78

80

LMA

(cm

2 )

a

a a a

b

58%53%

32%27%

41%

0%

10%

20%

30%

40%

50%

60%

70%

Per

cent

RA/IS/Rev N/IS/Rev N/RA/RA/Rev N/N/RA/Rev None

Percentages of Holstein steer carcasses grading USDA Choice or better

abc

cbc

aba

USDA Yield Grade

1

1.2

1.4

1.6

1.8

2

2.2

2.4

2.6

2.8

3

RA/IS/Rev N/IS/Rev N/RA/RA/Rev N/N/RA/Rev None

Treatment Group

Yie

ld G

rad

e

Meat

Ribs aged for 14 days 2 steaks from each rib were removed,

individually vacuum packed Steaks sent to Colorado State

University CSU measured tenderness (shear

force) and conducted trained taste panel

Warner-Bratzler Shear Force

4

4.2

4.4

4.6

RA/IS/Rev N/IS/Rev N/RA/RA/Rev N/N/RA/Rev None

Fo

rce

(kg

)

WB Shear Force over 5

0%

5%

10%

15%

20%

25%

30%

35%

RA/IS/Rev N/IS/Rev N/RA/RA/Rev N/N/RA/Rev None

Per

cent

Trained Taste Panel

5.4

5.5

5.6

5.7

5.8

5.9

6

RA/IS/Rev N/IS/Rev N/RA/RA/Rev N/N/RA/Rev None

Te

nd

ern

es

s (

1-8

)

ab ab

bcc

a

Summary

Early implants dramatically influence marbling at a given weight

Delaying implants tend to improve marbling without significant effects on growth & efficiency

Aggressive nature of implant strategy should complement the market

Variations in tenderness can not be explained by the use of implants

20

22

24

26

28

30

32

Pr- Ch+ Ch Ch- Se100 Se60 Se30 Std

Perc

ent E

mpt

y Bo

dy F

at

Percent Empty Body Fat

Percent Empty Body Fat

25.0

25.5

26.0

26.5

27.0

27.5

A B C D E

Em

pty

Bod

y Fa

t (%

)

a

abab

bb

480

500

520

540

560

580

A B C D E

Adju

sted

Fin

al B

ody

Wei

ght (

kg)

Adjusted Final Body Weight

480

500

520

540

560

580

A B C D E

Adju

sted

Fin

al B

ody

Wei

ght (

kg)

a

aa

a

b

0

20

40

60

A B C D E

Diff

eren

ce in

AF

BW

(kg

)AFBW from nonimplanted

Controls