Reference for Chullin 144:12

לימא ר' מאיר לטעמיה דתנן

[ACCORDINGLY], THE SLAUGHTERING OF A LIVE EIGHT MONTHS' BIRTH DOES NOT RENDER IT CLEAN, SINCE TO ITS KIND SLAUGHTERING DOES NOT APPLY.<span class="x" onmousemove="('comment',' An eight months' birth is not a viable animal and therefore slaughtering does not apply to it, for it is not within the category of cattle or sheep.');">⁴</span>

Jastrow