I just did the math, and when my vet had me give it to a 4 kg (8.8 pound) peahen she had me use 0.7 ml of a 1.5 mg/ml solution twice a day. I think that works out to ~0.26 mg/kg. So based on that, a 5 pound rooster would get only ~0.6 mg. Note that the dose is 0.6 mg, not 6 mg!
Does that help?
Does that help?