breed (v.) Look up breed at Dictionary.com
Old English bredan "bring (young) to birth, procreate," also "cherish, keep warm," from West Germanic *brodjan (source also of Old High German bruoten, German brüten "to brood, hatch"), from *brod- "fetus, hatchling," from PIE root *bhreu- "to boil, bubble, effervesce, burn." The etymological notion is incubation, warming to hatch.

Intransitive sense "come into being" is from c. 1200; that of "beget or bear offspring" is from mid-13c. Of livestock, etc., "procure by the mating of parents and rear for use," mid-14c. Sense of "grow up, be reared" (in a clan, etc.) is late 14c.; meaning "form by education" is from mid-15c. Related: Bred; breeding.
breed (n.) Look up breed at Dictionary.com
"race, lineage, stock from the same parentage" (originally of animals), 1550s, from breed (v.). Of persons, from 1590s. Meaning "kind, species" is from 1580s.