Water consumption of piglets

I would like to know the "effects of water consumption" in piglets. I mean, the real importance of this in any physiological process, since a trial was conducted where it was found that water supply was not essential during lactation. Those piglets that supplemented water with milk, compared with other groups that have water ad libitum, obtained a higher weight at weaning.

Milagros Puerta Oliva
Central University of Venezuela

(This question was taken from the Spanish community and translated into English)