Genesis 30:41 - Clarke's commentary and critical notes on the Bible

And it came to pass, whensoever the stronger cattle did conceive, that Jacob laid the rods before the eyes of the cattle in the gutters, that they might conceive among the rods. Whensoever the stronger cattle did conceive - The word מקשרות mekushsharoth, which we translate stronger, is understood by several of the ancient interpreters as signifying the early, first-born, or early spring cattle; and hence it is opposed to עטפים atuphim, which we translate feeble, and which Symmachus properly renders δευτερογονοι, cattle of the second birth, as he renders the word mekushsharoth by πρωτογονοι, cattle of the first or earliest birth. Now this does not apply merely to two births from the same female in one year, which actually did take place according to the rabbins, the first in Nisan, about our March, and the second in Tisri, about our September; but it more particularly refers to early and late lambs, etc., in the same year; as those that are born just at the termination of winter, and in the very commencement of spring, are every way more valuable than those which were born later in the same spring. Jacob therefore took good heed not to try his experiments with those late produced cattle, because he knew these would produce a degenerate breed, but with the early cattle, which were strong and vigorous, by which his breed must be improved. Hence the whole flock of Laban must be necessarily injured, while Jacob's flock was preserved in a state of increasing perfection. All this proves a consummate knowledge in Jacob of his pastoral office. If extensive breeders in this country were to attend to the same plan, our breed would be improved in a most eminent degree. What a fund of instruction upon almost every subject is to be found in the sacred writings!