SB 10.13.35
vrajasya ramah premardher
viksyautkanthyam anuksanam
mukta-stanesv apatyesv apy
ahetu-vid acintayat
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Because of an increase of affection, the cows had constant attachment even to those calves that were grown up and had stopped sucking milk from their mothers. When Baladeva saw this attachment, He was unable to understand the reason for it, and thus He began to consider as follows.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The cows had younger calves who had started sucking milk from their mothers, and some of the cows had newly given birth, but now, because of love, the cows enthusiastically showed their affection for the older calves, which had left off milking. These calves were grown up, but still the mothers wanted to feed them. Therefore Balarama was a little surprised, and He wanted to inquire from Krsna about the reason for their behavior. The mothers were actually more anxious to feed the older calves, although the new calves were present, because the older calves were expansions of Krsna. These surprising events were taking place by the manipulation of yoga-maya. There are two mayas working under the direction of Krsna maha-maya, the energy of the material world, and yoga-maya, the energy of the spiritual world. These uncommon events were taking place because of the influence of yoga-maya. From the very day on which Brahma stole the calves and boys, yoga-maya acted in such a way that the residents of Vrndavana, including even Lord Balarama, could not understand how yoga-maya was working and causing such uncommon things to happen. But as yoga-maya gradually acted, Balarama in particular was able to understand what was happening, and therefore He inquired from Krsna.