First lets start with definitions:
Encyclopedia Britannica definition :

wool, animal fibre forming the protective covering, or fleece, of sheep or of other hairy mammals, such as goats and camels. Prehistoric man, clothing himself with sheepskins, eventually learned to make yarn and fabric from their fibre covering. Selective sheep breeding eliminated most of the long, coarse hairs forming a protective outer coat, leaving the insulating fleecy undercoat of soft, fine fibre.
And what’s about the French “dictionnaire Larousse”? here also :
Fibre à croissance continue provenant de la toison des moutons et utilisée comme matière textile (La fibre de laine, qui est un sous-poil, est très résistante et peut être facilement filée et tissée.)
Fibre d'origine animale (alpaga, chameau, chèvre du Cachemire, guanaco, lama, lapin angora, chèvre mohair, vigogne, yack).
Fil à tricoter de laine pure, mélangée, ou de fibre synthétique. : Laine en pelote, en écheveau.
Tissu ou vêtement fait de laine : Porter de la laine.
(for those who don’t read French, they also agree with the Encyclopedia Britanica : wool is the animal fiber.)

Looking around world, at how other countries refer to the stuff off an alpaca’s back, wool seems to be the word of choice. Australia, New Zealand, and across Europe, breeders and industry professionals speak about Alpaca ‘wool,’ sheep ‘wool’ or Cashmere ‘wool.’

So, why in this country, do we still say alpaca ‘fiber’? Not that it is wrong, but the precise term should be “alpaca wool.” We respectfully submit that our dear judges should speak in a precise, industry accepted terms, and speak about alpaca wool. We, on our farm, and in our discussions, refer to the stuff off our alpaca’s backs as ‘wool.’ And we encourage others in the U.S industry to do the same. Alpacas produce a true luxury wool that competes more and more with Cashmere wool. Let’s be bold, and accurate in our use of the terms. It is alpaca wool!

Wool mill in Peru.