lakota:
In response to your original question, SDSU (as Andy has indicated) does lots of independent research on implanting and implanting strategies. They also have done some work comparing implants and leaving bulls intact and castrating later (at weaning.)
Here is a link to one piece of research they've done:
http://ars.sdstate.edu/extbeef/2004/BEEF_2004-11_Bruns.pdf
One thing to remember is that if you late castrate, you'll like lose some post weaning performance. I don't know when you market your calves, but this could have a pretty significant impact on pay weight if you sell shortly after weaning.
If you are looking for a way to regain some value from not implanting, and also aren't wanting to late castrate (versus castrating at branding, turnout, or in the springtime,) why don't you look at natural programs?
If you do market as "natural eligible", that means that you'll have to do more than not implanting, you'll also not be able to not market calves that have been treated with antibiotics as natural eligible, or feed those natural eligible calves antibiotics or feed additives, such as Rumensin or Tylan.
Haymaker, we don't implant, but I'll agree with FH that lots of independent studies have been completed that have not been funded by implant companies. Check out the above link and look around on SDSU's website. I think Robbie Pritchett is about as likely to be paid off as you would Haymaker. He's pretty independent, to say the least!
Andy is correct, if you implant, it certainly pays to "do it right." Oklahoma State University did a really interested study on the effects of abscessed implants. They showed that if implants were abscessed, cattle actually peformed worse than if they had not been implanted at all.
Lakota, I hope we've helped. Seriously, if the natural deal works into your management style, give it some thought. Likewise, to age verification. Both have been paying pretty good dividends.
Cheers---
TTB :wink: