How far are you pumping the water? Depending where my cattle are, I have two options.
The first option is a pasture pump. It is a large diaphram pump that the cattle actually pump using their nose to push the lever that pumps the water. The pump only has about a 25' head, but will pump vertically over 100'.
My local conservation agent lent me one last summer, and when he took it back, I bought one on Ebay. It is amazing how fast the cattle learn to use this device. I guess thirst is a great motivator!
UTINA Cattle Operated & Powered Pasture Pump N.O.S. - eBay (item 110253615691 end time May-19-08 17:37:28 PDT)
I bought one from this gentleman and received an as advertised pump in a timely fashion. You will need to buy some black poly water line at your local hardware store. It is available in rolls of 100' - 300'. You will also need to buy some BIG timbers to attatch the pump to. I drove a fence post into the bottom of my pond and attatched the pump intake to it. No more cattle in the pond ruining the banks and contaminating water.
My back pasture has no access to water and no power available. Bad combination. I use three 75 watt solar panels and a Solar Force pump to pump water up a 150' hill to a 1200 gallon tank. Water is gravity fed through 2100' of 3/4 inch water pipe to the back pasture. Pipe is not buried, so it is a 3 season system. Make sure you pay attention to pipe friction and the height of your holding tank if you opt for this setup. This system was also spendy, about $3000 two years ago. I already had the panels, and that reduced the cost some. It still beats option 3, which I did, filling a 350 gallon tank from the well, hauling it on a trailer to the cattle, and attatch it to a stock tank and float valve.
Good Luck!