Anabolic Implants

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Anabolic Implants

• Over 90 of feedlot cattle receive some type of
  anabolic implant during the finishing phase
• Increase average daily gain, feed intakes and
  improve feed efficiency
• Currently 22 implant products on the market
• Used for calves, stocker cattle, and finishing
  cattle
• Reduce beef production costs by 7

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Normal postnatal growth curves of bone, muscle,
and fat.
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Normal postnatal growth curves of bone, muscle,
and fat.
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Normal postnatal growth curves of bone, muscle,
and fat.
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How to Implant
1) Load Implant Gun with implant cartridge 2)
Insert needle between skin and cartilage in
middle third of the ear 3) Pull trigger and
retract needle 4) Check implant site with
thumb 5) Disinfect needle
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Hormones approved for use in growth promoting
implants

• 3 Natural HormonesEstradiolProgesteroneTestost
  erone
• 2 Synthetic hormonesZeranolTrenbolone acetate
  (TBA)

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Mode of Action

• Estrogenic (Estradiol and Zeranol
  implants)enhance muscle growth through
  increased production of growth hormone (via IGF)
• Androgenic (TBA and testosterone
  implants)enhance muscle growth by inhibiting
  the release of hormones that cause muscle
  degradation
• Combination (Estrogenic and Androgenic
  implants)additive effects

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Implant Products Available
Less aggressive
9
Implant Products Available
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Implant Products Available
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Summary-Growing Cattle

• Suckling calves Ralgro or Synovex-CSteers
  17/headHeifers 18/headReplacements--reduces
  pregnancy ratesCan implant once at 2 mo of age
  or at weaning without dramatic effect
• Stocker RalgroSteers 12.50/headHeifers
  11.50/head
• Influenced by forage availability, genetic
  potential, creep feeding

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Feedlot Steers
improvement over non-implanted steers
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Feedlot Steers
No effect on dressing percent, fat thickness,
KPH, or Yield grade
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Implant Types Steers
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Backfat and Marbling Regressed Against Hot
Carcass Weight
Bruns et. al.,1999
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Cattle x Implant Influences on Choice

• Implant Strategya
• Flesh Control Plus RevS RalRevS
• Avg 67 54 58 59
• Thin 69 32 44 60
• a Trt P lt .01 Block P.09
• 
  

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Early Calf Growth and Marbling

• Weaning Management
• Early Creep Normal
• ADG, kg
• 177-231dab 3.17 1.81 1.37
• 231-443da 2.82 3.04 3.04
• Marblinga 1198 1144 1120
• aEarly vs. rest (P lt .01)
• bCreep vs. normal (P lt .05)
• 1100 Modesto

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Relationship of empty body fat to Quality
Grade(Guiroy, 2001, total of 1,355 animals)
Mid Choice, 29.9 EBF
Low Choice, 28.6 EBF
Select, 26.2 EBF
Standard, 21.1 EBF
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Predicted EBF by USDA Grade
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Shrunk BW at 28EBF in Steers
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Implant effect on energy efficiency

• After accounting for BW and composition of gain
• Implanted Steers
• Apparent diet ME values were increased 4.2
• Implanted Heifers
• Apparent diet ME values were increased 3.1

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Conclusion

• After accounting for body weight and body
  composition implants improve diet energy
  utilization.
• Implant response is due to a combination of a
  reduced proportion of the DMI required for
  maintenance, reduced energy content of gain and
  efficiency of use of absorbed energy.

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Overall Summary

• Implants with increasing anabolic dose increase
  the finished weight of cattle at a common fat
  endpoint.
• Implants improve apparent diet ME over non
  implanted cattle adjusted for body weight and
  composition of gain.
• Implanted cattle can be expected to reach low
  choice at the same fatness as non-implanted
  cattle.