فَإِذَا بَلَغَتْ خَمْسًا وَعِشْرِينَ: فَفِيهَا بِنْتُ مَخَاضٍ، إِلَى خَمْسٍ وَثَلَاثِينَ.
Translation: At 25 camels, one bint makhad is due through 35.
At 25 camels, the due item changes from sheep to one bint makhad, remaining the same through 35. This is a defined age class of female camel, not merely any female.
The contrast at the threshold is substantial: 24 camels require four sheep, while 25 require one bint makhad.