וַיֶּחֱמ֥וּ הַצֹּ֖אן אֶל־הַמַּקְל֑וֹת וַתֵּלַ֣דְןָ הַצֹּ֔אן עֲקֻדִּ֥ים נְקֻדִּ֖ים וּטְלֻאִֽים׃
가지 앞에서 새끼를 배므로 얼룩얼룩한 것과 점이 있고 아롱진 것을 낳은지라
Radak on Genesis
ויחמו, a reference to the males. However, as we learned earlier, the females would be in heat simultaneously.