Reference for Chullin 7:1
גִּיד הַנָּשֶׁה נוֹהֵג בָּאָרֶץ וּבְחוּצָה לָאָרֶץ, בִּפְנֵי הַבַּיִת וְשֶׁלֹּא בִפְנֵי הַבַּיִת, בְּחֻלִּין וּבְמֻקְדָּשִׁים. וְנוֹהֵג בִּבְהֵמָה וּבְחַיָּה, בְּיָרֵךְ שֶׁל יָמִין וּבְיָרֵךְ שֶׁל שְׂמֹאל. וְאֵינוֹ נוֹהֵג בְּעוֹף, מִפְּנֵי שֶׁאֵין לוֹ כָף. וְנוֹהֵג בְּשָׁלִיל. רַבִּי יְהוּדָה אוֹמֵר, אֵינוֹ נוֹהֵג בְּשָׁלִיל. וְחֶלְבּוֹ מֻתָּר. וְאֵין הַטַּבָּחִין נֶאֱמָנִין עַל גִּיד הַנָּשֶׁה, דִּבְרֵי רַבִּי מֵאִיר. וַחֲכָמִים אוֹמְרִים, נֶאֱמָנִין עָלָיו וְעַל הַחֵלֶב:
The precept concerning the prohibition of eating the "sinew which shrank" [גיד הנשה] is obligatory in and out of the Holy Land, during and after the existence of the Temple, in animals slaughtered for profane use [חולין], and in respect also to consecrated sacrifices, and applies to wild and domestic animals, and to both the right and left thighs of the animal; it does not apply to fowl, since these have no "hollow in the thigh." It applies to a fetus in embryo, and its suet [חלב] it is permitted to use. According to R. Meir, "The assertion of butchers in respect to their having removed the גיד הנשה [sciatic nerve] is not to be relied on;" but the sages hold, "That they may be relied on in this respect, and in that of the removal of חלב, or suet."