Chulin6: 4
שָׁחַט מֵאָה חַיּוֹת בְּמָקוֹם אֶחָד, כִּסּוּי אֶחָד לְכֻלָּן. מֵאָה עוֹפוֹת בְּמָקוֹם אֶחָד, כִּסּוּי אֶחָד לְכֻלָּן. חַיָּה וָעוֹף בְּמָקוֹם אֶחָד, כִּסּוּי אֶחָד לְכֻלָּן. רַבִּי יְהוּדָה אוֹמֵר: שָׁחַט חַיָּה, יְכַסֶּנָּה, וְאַחַר־כָּךְ יִשְׁחֹט אֶת־הָעוֹף. שָׁחַט וְלֹא כִסָּה, וְרָאָהוּ אַחֵר, חַיָּב לְכַסּוֹת. כִּסָּהוּ וְנִתְגַּלָּה, פָּטוּר מִלְּכַסּוֹת. כִּסָּהוּ הָרוּחַ, חַיָּב לְכַסּוֹת.
[If] one slaughtered a hundred beasts in one place, one covering [suffices] for them all. A hundred fowl in one place, one covering [suffices] for them all. A beast and a fowl in one place, one covering [suffices] for them all. R’ Yehudah says: [If] he slaughtered a beast, he must cover it[s blood], and afterwards slaughter the fowl. [If] he slaughtered and did not cover [the blood], and someone else saw it, he is required to cover it. [If] he covered it and it became uncovered, he is exempt from covering [it]. [If] the wind covered it, he is required to cover [it].
Chulin6: 5
דָּם שְׁנִּתְעָרֵב בְּמַיִם — אִם יֶשׁ־בּוֹ מַרְאִית דָּם, חַיָּב לְכַסּוֹת. נִתְעָרֵב בְּיַיִן, רוֹאִין אוֹתוֹ כְּאִלּוּ הוּא מַיִם. נִתְעָרֵב בְּדַם הַבְּהֵמָה אוֹ בְדַם הַחַיָּה, רוֹאִין אוֹתוֹ כְּאִלּוּ הוּא מַיִם. רַבִּי יְהוּדָה אוֹמֵר: אֵין דָּם מְבַטֵּל דָּם.
[If] blood mixed with water — if it has the color of blood, he is required to cover [it]. [If] it mixed with wine, we view it as if it were water. [If] it mixed with the blood of an animal or with the blood of a beast, we view it as if it were water. R’ Yehudah says: Blood cannot nullify blood.