Alas, no water trough in that field, the photo you link conveniently includes in the background the water source that the sheep were using.
Julia
Julia
The cola bottles are really thin sometimes. My wife drinks Sainsburys (mostly, cheap for 4, but almost any supermarket make) flavoured still water, 1L. They're fairly thick, and a good shape. The sparkling bottles have a long tapering neck which makes the bottle long, but they are stronger (to handle the pressure) than the still water one.
Also, if you dip the water bottle into the source to fill it remember that the outside of the bottle will now be contaminated.
Another good one is Robinsons Barley Water squash bottles, they are really think and last well.