OPINIONS: In the Mishnah (30b), Rebbi Chanina ben Antignos says that a Kosher animal that nursed from a Tereifah may not be offered as a Korban on the Mizbe'ach. The Gemara first assumes that Rebbi Chanina refers to any animal that was fattened through drinking the milk of a Tereifah. The Gemara asks that if such an animal is forbidden to be offered as a Korban, then an animal that ate grains used for Avodah Zarah should be forbidden as well. The Gemara answers that Rebbi Chanina ben Antignos refers to an animal that drank the milk of a Tereifah every day, and could go without eating for more than twenty-four hours after such a feeding.
Does Rebbi Chanina ben Antignos rule only that such an animal may not be offered on the Mizbe'ach as a Korban, or does he maintain that such an animal is prohibited even to be eaten by an ordinary person?
(a) TOSFOS (DH she'Yankah Chalav Rose'ach) writes that the Gemara's conclusion applies to animals that live off of the grains of Avodah Zarah as well. He adds that the Gemara implies that such an animal is also prohibited to be eaten by an ordinary person.
There seem to be two ways to understand the words of Tosfos.
1. The REMA (YD 60:1) rules that an animal that was fattened with forbidden food is permitted to be eaten. However, if it was fattened every day primarily from forbidden food, then it is prohibited. The Rema apparently understands that Tosfos maintains that the conclusion of the Gemara applies to all forbidden foods.
2. The SHACH (YD 60:5) understands Tosfos differently. According to the Shach, although an animal is unfit to be a Korban when it was nurtured primarily from forbidden foods, it is unfit to be eaten by a person only when it was nurtured primarily from grains of Avodah Zarah, which are Asur b'Hana'ah. (See the Shach there at length.)
The ARUCH HA'SHULCHAN (YD 60:7) explains that Tosfos does not differentiate between foods that one may not eat (Asur b'Achilah) and foods from which one may not derive any benefit (Asur b'Hana'ah). Rather, Tosfos means that because of the severity of Avodah Zarah and the caution which one must exercise in order to stay away from any form of benefit from Avodah Zarah, a person should derive no benefit from an animal that was raised on grains of Avodah Zarah.
The Aruch ha'Shulchan concludes that many Poskim, including the KEREISI U'PLEISI and MAHARIT, rule this way. He concludes that the Shach's opinion also "leans towards" this explanation ("Noteh"). (It seems that the Aruch ha'Shulchan understands that the main point of the Shach is that the grains were grains of Avodah Zarah, and not that they were grains that were Asur b'Hana'ah. However, this does not seem to be supported by the simple reading of the Shach.)
(b) The RAMBAM (in Perush ha'Mishnayos) argues with Tosfos in two ways. The Rambam maintains that this Halachah was said only with regard to prohibiting an animal from being offered as a Korban, and not with regard to prohibiting it from being eaten by a person. Moreover, he writes that the Halachah does not follow the view of Rebbi Chanina ben Antignos.
The Rambam therefore rules that not only may a person eat from an animal that was fattened -- even exclusively -- by food of Avodah Zarah food, but such an animal may even be offered as a Korban. (Y. MONTROSE)


OPINIONS: The Mishnah lists the Halachos unique to each of the two categories of Hekdesh, Kodshei Mizbe'ach and Kodshei Bedek ha'Bayis. The Mishnah lists the stringencies of each category over the other. One of the stringencies of Kodshei Bedek ha'Bayis is that it is possible to commit Me'ilah even with the "Gidulin" -- literally, the "growths" of Kodshei Bedek ha'Bayis, while one cannot commit Me'ilah with the Gidulin of Kodshei Mizbe'ach. The Gemara concludes that even according to the opinion that Gidulin of Kodshei Mizbe'ach are subject to Me'ilah, they are subject to Me'ilah only when the growths themselves are fit to be offered on the Mizbe'ach.
What is a type of growth that is fit to be offered on the Mizbe'ach?
(a) RASHI (DH Gidulin d'Chazi l'Mizbe'ach) explains that the Gemara refers to the offspring of animals of Kodshei Mizbe'ach. Those offspring are fit to be offered on the Mizbe'ach.
TOSFOS (DH v'Afilu l'Man d'Amar) questions this explanation from the Gemara earlier (17b). The Gemara derives from the verse, "Yiheyu Lecha" -- "they will be to you" (Devarim 12:26), that the offspring of Kodshim are like Kodshim themselves. Tosfos understands that this verse is the source that the offspring of Kodshei Mizbe'ach are like their parents (and thus Me'ilah applies to them), and not the fact that they happen to be Gidulin of Kodshei Mizbe'ach.
Tosfos asks another, stronger question on Rashi's explanation. There is no opinion anywhere in the Gemara that maintains that it is possible to commit Me'ilah with the offspring of Kodshei Mizbe'ach. How can Rashi say that there is such an opinion? (See TEMURAS TODAH for a possible answer for Rashi.)
(b) Tosfos therefore asserts that the Gidulin mentioned here refer to the blood of an animal. His source is the Gemara in Me'ilah (12b). The Gemara there quotes Ze'iri who states that it is possible to commit Me'ilah with the blood gathered from the bloodletting of an animal of Kodshim. The Gemara there questions this ruling from the Mishnah that states that one may not benefit from the milk of Kodshim or from the eggs of Torin (doves sanctified as Korbanos), but one nevertheless does not commit Me'ilah if he benefits from them. The Gemara's question there implies that the Gemara maintains that blood has the same status as milk and eggs, which clearly have the status of Gidulin. It must be that the Gemara here, which mentions Gidulin of Kodshei Mizbe'ach that are fit to be offered on the Mizbe'ach, refers to the blood of Kodshim, and the opinion referred to is that of Ze'iri.
The OLAS SHLOMO asks that blood extracted from an animal through bloodletting is not fit for the Mizbe'ach. The Gemara in Zevachim (25a) states that the blood required for Zerikas ha'Dam is called "Dam ha'Nefesh," which refers to blood that comes out of the animal after the original loss of blood (see Kerisus 22a for a discussion of exactly what is considered Dam ha'Nefesh). Tosfos in Kerisus (20b, DH Dam Hakazah) clearly states that it is highly unusual for the bloodletting of an animal to produce such blood. Accordingly, how can Tosfos say that when the Gemara here refers to Gidulin of Kodshei Mizbe'ach that are fit to be offered on the Mizbe'ach, it refers to blood gathered from bloodletting? Such blood is not Dam ha'Nefesh and is not fit for the Mizbe'ach! The Olas Shlomo concludes that Tosfos must maintain that Ze'iri is discussing the unusual case in which the bloodletting indeed caused the Dam ha'Nefesh to emerge. (Y. MONTROSE)