Reference for Bekhorot 41:3

אמר רבי שמעון אני ראיתי גדייה כו':

- [No], though you hold that an animal which discharges can give birth in the year [of its discharging],<span class="x" onmousemove="('comment',' I.e., that the period of discharging can be less than thirty days.');">³</span>

Jastrow