Minchi - that information is strictly not true, it sounds like the Parker Planning Commission gave you the run around.
According to the current housing zoning laws, in the municipal code 13.4.190, residents are allowed up the 50 fowl per parcel (property). However, in subsection (c) you are required to house the birds at least 200 ft from an offsite residence or business. This is a prohibitive distance for most suburban residents (though not if you have a large plot).
I, among others, are asking the town council to amend 13.4.1909(c) to allow for small flocks with a minimum distance of 15ft or so, to be in line with restrictions in other cities like Denver and HR. The number of birds in the small flock is up for debate, but the intention is to let suburban residences keep hens without worrying about the 200ft distance. Please contact the mayor and/or town council voicing your support!