Taharos 1:3 - 1:4

נבלת עוף טמא – that its end is not to defile a stringent defilement/uncleanness which does not defile humans and garments.

צריכה מחשבה – that he will intend to eat/consume it.

והכשר (and preparation)– of water or the rest of the liquids [for susceptibility to defilement], and afterwards it will come in contact with a creeping animal.

לפסול את הגויה (to render the body unfit) – if it had been defiled, and he ate from half a loaf’s bulk, which is an egg and a half [of an egg], his (i.e., that of a Kohen) body is made unfit to eat heave-offering until he immerses [in a Mikveh].

ואין בה כזית בבית הבליעה – as it is written (Leviticus 22:8): “He shall not eat anything that died or was torn by beasts.” He whose prohibition is because of the food of a carrion defiles through eating in the esophagus, excluding this whose prohibition is not because of eating carrion but rather because of eating anything that is impure/

והאוכלה אין טעון הערב שמש – the person who consumes half of a loaf of it after it was defiled, for he invalidates the body to eat heave-offering, if he immersed [in a Mikveh] after he consumed it, he is permitted [to consume] heave-offering immediately, and does not require [the arrival of] a sunset.

ואין חייבין עליה על ביאת מקדש – if he ate one-half a loaf of carrion of an impure bird and entered into the Sanctuary, it is defilement of the Rabbis, and even though that burn heave-offering upon it.

והאוכל אבר מן החי ממנה סופג את הארבעים – and even though that eat an olive’s bulk whether it is flesh or sinews and bones, for now even according to the one who holds that [eating] the limb of a living animal requires an olive’s bulk for eating is written regarding it, here there is an olive’s bulk, nevertheless, he does not receive forty (really, thirty-nine) lashes. But because of something impure, he is not obligated, for there isn’t an olive’s bulk of flesh.

ואין שחיטתה מטהרתה (for slaughtering it does not render it clean) – for eating. For a son of Noah who is permitted [to consume] an impure bird but is prohibited from [consuming] the limb of a living animal, but if he slaughtered it and it is moves convulsively/kicks, his slaughtering of it does not purify it for eating until it dies. Even though that with a clean [animal] even it is convulses, the slaughter is permitted for a son of Noah, in consequence of that it would be fit for an Israelite (i.e., the legal status required for its legitimacy might have easily been obtained). And this is how our Mishnah is explained at the end of the chapter, “The Sciatic Nerve”/גיד הנשה (see Talmud Tractate Hullin 102a).

ובבהמה העור והרוטב – all of this Mishnah is explained in Tractate Hullin, in the Chapter "העור והרוטב"/The Hide and the Fat/Juice (Chapter 9 of Tractate Hullin, Mishnah 1).