Reference for Bekhorot 84:29

אית דאמר אישתני ואית דאמר לא אישתני

- [The question can be met in this way]: One authority [the first Tanna quoted in the above Baraitha] holds: Since its condition has changed, it is a different animal [and therefore it possesses holiness] whereas the other authority, [R'Simeon] holds: We do not say [with reference to an animal] that since its condition has changed, it is therefore a different animal.<span class="x" onmousemove="('comment',' And therefore we maintain that the animal was originally a female, in which case there is no holiness whatsoever. R. Elai will consequently agree with R. Simeon.');">¹⁹</span>

Jastrow

Jastrow