All urine quickly breaksdown to mainly ammonia once exposed to air. Most biologists I know that have no interest or monetary ties to the industry tell me that urines "practical, effective life" is a matter of hours if a day at most. Past that I suspect it's a curiousity scent to deer. If you think about it, even after the deer pee on the ground that urine instantly begins to breakdown. BUT that suggests to me that the deer dont seem to neccessarily mind that "old" stuff as they certainly come in to daily contact with it in their daily world.
I've always thought the FRESHEST possible would be taken yourself via a syringe from a freshkill. But I've honestly never messed with it. I have done the old "remove the tarsal glands & drag them behind your boots" (from does & bucks) but can say that I never saw more than the occasional doe or toy buck come in on such a trail.
I think the only "gamechanger" you could theoretically chance would be to harvest a cycling doe during the rut & use that urine for a day or so. But even then the odds of that all hapening are pretty slim. Plus during the "prime chasin time" the LAST thing I want to mess with is a doe & if shes hot I'd much rather keep her around for "live bait!"
Last edited by HatchieLuvr; 10-11-2012 at 12:26 PM.