Reference for Chullin 145:36

שחיטת אמו

differ with regard to the [limb of the] foetus so they differ with regard to loose limbs.<span class="x" onmousemove="('comment',' According to R. Meir the slaughtering of the animal will not render the hanging limb clean, but according to the Sages it will.');">¹¹</span>

Jastrow