Bechoros 2:3-4

Bechoros 2:3

If the animal was consecrated before being blemished, or if it developed a temporary blemish before being consecrated and a permanent blemish emerged later, and it was redeemed, it is exempt from firstborn status and from the potions given to a kohein. It does not become secular so it may not be shorn, nor used for work. Its offspring and milk are prohibited after it has been redeemed, one is liable for slaughtering it outside the Temple, the rules of substitution apply to it and if it dies, it must be buried.

Bechoros 2:4

If one receives “iron sheep” animals (a type of investment arrangement) from a non-Jew, their offspring are exempt from the laws of firstborn animals (because of the non-Jew’s lien on them), but the offspring’s offspring are obligated (since the Jew owns them free and clear). If he made the offspring collateral for their mothers, then the offspring’s offspring are exempt but the offspring’s grand-offspring are obligated. Rabban Shimon ben Gamliel says that the offspring are exempt even to the tenth generation because the non-Jew has a lien on all of them until the debt has been paid.