Hi , Rompum, a long time since i heard that, We used bottles of the stuff to get the velvet off the deer at home in the 1980s we started with 1ml and got down to .1 of a ml per red stag as long as it was in the dark, as you probably know daylight is the wake up serum,
I dont know what they use now as I left in 86
We did manage to move deer from one place to another very easily with out drugging them just build an appropriate race and load them onto an appropriate stock trailer or truck,
You dont allways have to shoot them or drug them to get them off your park,
when you say park, are they fenced in?? if so just let some out the gate to chance their arm in the wild!
good luck with Rompun!!