יורה דעה נ״טYoreh De'ah 59

Se’if 1א׳

הַגְּלוּדָה אֲסוּרָה, וְהִיא שֶׁנִּפְשַׁט עוֹרָהּ בֵּין בִּידֵי אָדָם בֵּין בִּידֵי חֹלִי, טְרֵפָה. וְאִם נִשְׁתַּיֵּר מִן הָעוֹר רֹחַב סֶלַע עַל פְּנֵי כָּל הַשִּׁדְרָה וְרֹחַב סֶלַע עַל הַטַּבּוּר וְרֹחַב סֶלַע עַל רָאשֵׁי אֵיבָרֶיהָ, הֲרֵי זוֹ מֻתֶּרֶת (רַמְבַּ"ם וְרַשְׁבָּ"א וְר"ן וְרֹב הַפּוֹסְקִים). וְאִם נִטַּל כְּרֹחַב סֶלַע מֵעַל כָּל גַּבֵּי הַשִּׁדְרָה אוֹ מֵעַל הַטַּבּוּר אוֹ מֵעַל רָאשֵׁי אֵבָרִים, וּשְׁאָר כָּל הָעוֹר קַיָּם, כְּשֵׁרָה. הַגָּה: אֲבָל אִם נִטְּלָה מִשְּׁלָשְׁתָּם וּשְׁאָר כָּל הָעוֹר קַיָּם, טְרֵפָה (ד"ע).

An animal whose hide has been flayed off, the geludah, is forbidden; and that is one whose hide was stripped off, whether by the hand of man or by the hand of illness: it is a tereifah (an animal with a fatal defect). And if there remained of the hide the breadth of a sela over the whole of the spine, and the breadth of a sela over the navel, and the breadth of a sela over the tips of its limbs, this is permitted (Rambam and Rashba and Ran and most of the poskim). And if the breadth of a sela was taken from over the whole of the spine, or from over the navel, or from over the tips of the limbs, and all the rest of the hide stands, it is fit. Hagah [Rema]: But if it was taken from all three of them and all the rest of the hide stands, it is a tereifah (his own opinion).

Se’if 2ב׳

הָעוֹף שֶׁנִּטְּלָה נוֹצָתוֹ, כָּשֵׁר (בֵּית יוֹסֵף בְּשֵׁם רֹב הַפּוֹסְקִים וכ"פ מַהַרְשַׁ"ל פא"ט סִימָן ק"ט). הַגָּה: וְיֵשׁ אוֹסְרִים (ר"ז הַלֵּוִי וְכָל בּוֹ). וְטוֹב לְהַחְמִיר אִם נָפְלוּ כֻּלָּם. מִיהוּ אִם נָפְלוּ נוֹצוֹתָיו מֵרֹב שֻׁמָּן, אַף עַל פִּי שֶׁנָּפְלוּ כֻּלָּם וְנִשְׁאַר עָרֹם, מִכָּל מָקוֹם כָּשֵׁר דְּהוֹאִיל וְנַעֲשָׂה מֵרֹב שֻׁמָּנוֹ, כָּשֵׁר. (ת"ה סִימָן קפ"א בְּשֵׁם אוֹר זָרוּעַ).

A bird whose plumage has been removed is fit (Beit Yosef in the name of most of the poskim, and so the Maharshal ruled, chapter "These are the tereifot", siman 109). Hagah [Rema]: And there are those who forbid it (Rabbi Zerachiah haLevi and Kol Bo). And it is well to be stringent if they all fell out. However, if its feathers fell out from the abundance of its fat, even though they all fell out and it remained bare, in any case it is fit; for since it came about from the abundance of its fat, it is fit. (Terumat haDeshen, siman 181, in the name of Or Zarua.)