Rashi on Genesis 32:16/רש"י על בראשית ל״ב:ט״ז

1גמלים מיניקות MILCH CAMELS שלשים THIRTY, ובניהם means AND THEIR COLTS with them — A Midrashic explanation of ובניהם is that it is the same as וּבַנָּאֵיהֶם their builders (those that build them up) i.e., one male for each female. Because, however, it (the camel) is chaste in its ways Scripture does not state this plainly (Genesis Rabbah 76:7) but employs a term from which it may be inferred.

2ועירים means MALE ASSES.