ancestry vs breed line

ancestry and breed line both are nouns.

Word	Noun	Adjective	Verb	Adverb
ancestry	Yes	No	No	No
breed line	Yes	No	No	No

As nouns, breed line is a hyponym of ancestry; that is, breed line is a word with a more specific, narrower meaning than ancestry:

ancestry: the hereditary derivation of an individual
breed line: Breed line is offspring from the mating or breeding of individuals or organisms that are closely related genetically.

Other hyponyms of ancestry include family, family line, folk, kinfolk, kinsfolk, phratry, sept, side.

ancestry (noun)	breed line (noun)
inherited properties shared with others of your bloodline	Breed line is offspring from the mating or breeding of individuals or organisms that are closely related genetically.
the hereditary derivation of an individual