Yes, CROSSBREEDS is a Scrabble word!

Letter values in Scrabble US: C 3, R 1, O 1, S 1, S 1, B 3, R 1, E 1, E 1, D 2, S 1.

Is it a valid word?

CROSSBREEDS is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

(genetics) an organism that is the offspring of genetically dissimilar parents or stock; especially offspring produced by breeding plants or animals of different varieties or breeds or species

Not playable in Scrabble US: HYBRIDISE.