FIL Tell Tail Paint aerosols can be used as tail paint, or as very good general purpose stock markers particularly suitable for cattle (not for use on wool).
Colours are fluoro, and are highly visible and will usually last up to four weeks, even in wet weather.
So as well as being genuine tail paints for mating identification, they are also ideal for warning marks in the dairy.
Another great feature with FIL is that the can empties its full contents, even if used horizontally. 
One can will do 40-50 average tail marks. Net contents 500ml.