1. זרוע לחיים וקבה for כלאים and כוי

In a Baraisa, the Rabbonon say that זרוע לחיים וקבה applies to both כלאים – a crossbreed and a כוי. Rebbe Eliezer says the מתנות apply to כלאים born from a goat and sheep (both of which are subject to מתנות), but a כוי, which comes from a goat and a deer, is exempt. The Gemara explains that the machlokes pertains to the offspring of a male deer and a female goat. All the Tannaim are uncertain אי חוששין לזרע האב – whether we are concerned with the father’s seed, i.e., whether the offspring is considered partly a חיה and partly a בהמה, or entirely a בהמה. Rebbe Eliezer holds שה ולא מקצת שה – the term "שה" in the obligation of מתנות does not include a part-שה, so a כוי is exempt. Rav Huna bar Chiya explains that although the Rabbonon hold שה ואפילו מקצת שה – the term "שה" includes even a part-שה, a Kohen is only entitled to half the מתנות. Regarding the second half, the owner can say: אייתי ראיה דאין חוששין לזרע האב ושקול – bring proof that we are not concerned for the father’s seed (and it is a full-fledged בהמה) and then take the second half. Ravin quotes Rebbe Yochanan that the Rabbonon obligate a כוי in the full מתנות, based on a derashah.

1. זרוע לחיים וקבה in the case of בכור שנתערב במאה

The next Mishnah states: בכור שנתערב במאה – if a bechor became mixed among a hundred animals, then בזמן שמאה שוחטין את כולן – if one hundred [people] shecht all of them, they are all exempt from giving זרוע לחיים וקבה, because each owner can claim that his animal was the bechor (and the Kohen must prove otherwise to demand the מתנות). If one person shechts all one hundred animals, the bechor exempts him from the מתנות of only one animal, since all except for one are obligated in מתנות. [However, he may choose which animal to exempt and claim it is the bechor.] The Gemara wonders why a bechor mixed among his animals exempts him from מתנות altogether: יבא עליו כהן משני צדדין – let the Kohen challenge [the owner] from both sides: if a particular animal is the bechor, it is entirely his, and if it is not, he is at least entitled to its מתנות!? Rav Oshaya answers that the Mishnah’s case is where the bechor was already given to a Kohen, and sold to a Yisroel after developing a מום. As a bechor, it is exempt from מתנות.

1. הדין עם הטבח; a טבח כהן

The Mishnah taught that one who shechts an animal for a Kohen or idolator is exempt from מתנות. The Gemara wonders why the Mishnah mentions the שוחט, and Rava says: זאת אומרת הדין עם הטבח – this teaches that the Kohen’s claim is on the slaughterer (i.e., when he shechts for a Yisroel, the Kohen may claim the מתנות from him). Rava darshened "מאת העם" – from the people to exempt Kohanim themselves from giving מתנות. However, the phrase "מאת זובחי הזבח" – from those who shecht includes even טבח כהן – a שוחט who is a Kohen; when he shechts his own animal to sell the meat, he must give the מתנות to another Kohen. Rav Nachman related that a Kohen who is a שוחט is exempt from מתנות for two or three weeks, while his business is not yet established; afterward, he is obligated. Furthermore, קבע מסחתא – if he established a store, he is immediately obligated to give מתנות. Rav Chisda said that a Kohen who does not give מתנות should be excommunicated.