Genesis 30:41

המקשרות THE STRONGER—Explain it as the Targum renders it: הבכירות the early-bearing sheep; but I have no evidence in the Scripture (i.e. I have no other example of the use of this word) to prove that this is its meaning. Menachem classifies it under the same root as (2 Samuel 15:31) “Ahitophel is among the conspirators (בקשרים)”, and as (2 Samuel 15:12) “And the conspiracy (הקשר) was strong” — so that the meaning would be those sheep that banded themselves together (mated) in order to accelerate their pregnancy (i.e. in order that they might become בכירות, early-bearing sheep).

וְהָיָ֗ה בְּכׇל־יַחֵם֮ הַצֹּ֣אן הַמְקֻשָּׁרוֹת֒ וְשָׂ֨ם יַעֲקֹ֧ב אֶת־הַמַּקְל֛וֹת לְעֵינֵ֥י הַצֹּ֖אן בָּרְהָטִ֑ים לְיַחְמֵ֖נָּה בַּמַּקְלֽוֹת׃

And it came to pass, whenever the stronger cattle did conceive, that Ya῾aqov laid the rods before the eyes of the cattle in the gutters, that they might conceive among the rods.