1. Delayed Implant Overview
Intervet, Inc.
Technical Services Team

2. Delayed Implanting
The use of delayed implant regimes have been investigated for many years. The first published delayed implant trial was conducted by Dr. John Matsushima many years ago, which indicated there may be some advantages to delayed implant strategies. However, more recent studies have shown no significant and repeatable improvements in feedyard performance or carcass characteristics.
This does not mean delayed implant strategies cannot be utilized in some special instances. It does indicate that there is no reason to utilize delayed implant strategies as a common practice.
Implant strategies have evolved over the last years as more good research has been conducted and analyzed. We, as an industry, have learned a great deal about growth physiology and how anabolic implants effect the growth patterns of today’s cattle. There is still much more to learn and the individuals, universities, and pioneer companies conducting the research are dedicated to finding the answers.
We in Intervet Technical Services are also dedicated to finding answers to these and many other questions that the industry considers important.

3. Delayed Implanting
In response to a recent article by Dr. David Price, we have summarized the recent trials which have been conducted with delayed implant strategies.
“Low-dose Implants and Delayed Implanting a Worthy Practice Feed-Lot Magazine. Feb. pp. 34”
Dr. Price tended to indicate in his article that not all data was available.
Included in this review are the recent trials that have been conducted and all have been published in some format.
“Grading is a touchy subject with implant manufacturers and not all companies have been so candid” Feedlot Magazine. Feb. pp. 34
A vast majority of trials conducted with implants include carcass data.
A large majority of research dollars are expended dealing with this subject
Intervet and formerly Hoechst-Roussel Vet has always dealt with this subject by investing very large sums of research dollars and conducting good, well replicated trials in order to find some definitive answers.
As a Pioneer Company, Intervet will continue to invest in sound research to assist you in developing the most profitable implant strategies.
We are also positive that Ft. Dodge Animal Health will invest in sound research as well.

4. Summary of Delayed Implant Trials.

5. Initial Implant Strategies Iowa Trial - Trenkle
Small pens

6. Initial Implant Strategies Iowa Trial - Trenkle
Small pens

7. Initial Implant Strategies Texas Trial, 1998
2,333 hd, 4 pens/trt

8. Initial Implant Strategies SDSU Trial, 1998
480 hd, 10 hd/pen, 8 pens/trt

9. Initial Implant Strategies Nebraska Trial, 1998
480 hd, 8 hd/pen, 10 pens/trt

10. Initial Implant Strategies Idaho Trial, 1998
384 hd, 8 hd/pen, 8 pens/trt

11. Initial Implant Strategies Nebraska, 1998
10,674 hd (445 hd/pen), 8 pens/trt
a,b Means in a row differ (P<.05)
c,d Means in a row differ (P<.17)

12. Implant Strategies NCBA Study, 1998

13. Delayed Implanting Strategies with Syn-Plus, Jim, 1999 TR#30
480 head, 10 pens/trt, 12 hd/pen
a,b Means in a row with different superscripts differ (P<.05)

14. Delayed Implanting Strategies with Syn-Plus, Milton, 1999 TR#32
225 hd, 5 pens/trt, 9 hd/pen
a,b Means in a row with different superscripts differ (P<.05)

15. Delayed Implanting Strategies with Syn-Plus, Jim, 1999 TR#23
480 head, 10 pens/trt, 12 hd/pen
a,b Means in a row with different superscripts differ (P<.05)

16. Synovex-Choice #TR-01
839 hd, 12 hd/pen, 10 pens/trt

17. Synovex-Choice #TR-02
960 hd, 12 hd/pen, 10 pens/trt

18. Delayed Implanting vs Reimplant Summary

19. Delayed Implanting vs Single Implant Summary

20. Technical Reference Articles – Ft. Dodge Animal Health
Delayed Implanting Conclusions By Dr. Kee Jim (Feedlot Health Management Services)
Technical Reference Articles – Ft. Dodge Animal Health
“A review of “delayed” trenbolone acetate/estradiol implant strategies for yearling steers”.
Potential benefits of delaying
Reduction in riding activity
Improved grading
Potential Negative Effects of delaying
Decreased ADG
Increased F/G
Decreased Total Gain
Possible Additional Cattle Handling

21. Delayed Implanting Conclusion By: Intervet Technical Service
Generally, reduces ADG, DMI, and Total Gain.
Feed to Gain is equal or worse numerically.
Grade is equal; numerically some better, some worse; never statistical.
Delayed implanting was never better than single or reimplant. A downside potential was exhibited in some trials, while being equal in others. Never better.
DMI reduced in most trials. Is this important in terms of overall feedyard performance and health aspects?
Bullers are reduced in some trials.
In heavy weight yearlings with high incidence of bullers, delayed implanting might be considered.
If utilized, delayed implanting should probably be 30 days or less.
Delayed implanting might be considered in some cases where lighter weights at finish may be important.