Yoreh Deah Siman 24 Seif 20

כ הַשּׁוֹחֵט תַּרְנְגוֹל צָרִיךְ לִזָּהֵר שֶׁיִּדְחֹק רַגְלוֹ בַּקַּרְקַע, אוֹ יַגְבִּיהֶנּוּ שֶׁלּא יִנְעֹץ רַגְלוֹ בַּקַּרְקַע, כְּדֵי שֶׁלֹּא יַעֲקֹר הַסִימָנִים.

Seif 20

 

When one slaughters a rooster one needs to take heed and squeeze his feet on the on the ground or lift him up so that his feet do not wedge in the ground in order that he does not dislodge the signs.