Reference for Chullin 148:19

רבי יהודה אומר

and ploughing with it.<span class="x" onmousemove="('comment',' Yoked together with an animal of a different species. Cf. Deut. XXII, 10. These prohibitions, it is agreed by all, apply (so Rashi; according to R. Gershom: do not apply) to an animal that was extracted out of the womb.');">⁹</span>

Jastrow