I haven't raised dogs for many years, but IMO, By 5 years of age if the dog hasn't shown to amount to much, most likely it ain going to...
If mine ain't rolling good by 2 years and doing something on their own, that's too long for me... Again just my opinion of what I want out of a dog...

thanks man 2 years is wat i was leaning toward, because 4 n 5 years is too long
just an example i got three ten month old pups right now all three bay hogs in a pen
been working cow w/ em and only one will stay hooked when a cow breaks n runs over 400 r 500 yards
all three will bay n drive as long as Im close by but just think ten month old is a little young to cull