The Shaakhas of the Vedas are explantions and / or editions of the original Samhitas (Vedas); and thus not the original Vedas. They may be even mixed up with the Brahmanas. So they are the creation of leter Vedic Seers. In the past there where 1127 Shakhas of the Vedas including 20 of the RigVeda, 100 of the Yajurveda, 1000 of the SamVeda and 7 of the AtharvaVeda.
But at present only a few (8-10) Shakhas are available.