Tuna,

Sure, you can do it. Whether it's worth the bother depends on the quality of the feathers and how much time it takes you to do a good job skinning the neck and saddle patch from the carcass. The fly tying material market has extremely high grade necks these days at almost reasonably affordable prices, so home grown hackle has become less popular except for the hard core who devalue the time they devote to raising and procuring hackle and other material.

Sincerely,

Salmo g.