My experience with windmills tells me that you should lift water with a submerged pump and use a large check valve to be able to lower the piston quickly. So, converting your vertical power shaft to a water lifting mechanism is do-able with the right transmission. I would have recommended a more conventional cyclic powerhead using, say a small gas engine shortblock or compressor body as a secondary option to pump air to an air motor water pump at the pond or better, just use a conventional water pumping windmill system. Livestock need a reliable water supply at all times.
The main consideration is what volume of water does it take (say in a given day or week) to supply the number of animals expected. That sizes the machinery along with how much wind do you have over the course of time. No problem with too much water, but not enough is a bad situation.
A conventional, 'vintage' windmill with an 8' wheel is good for about 1-1/2 hp in a strong wind, but has time on its side as far as pumping water volume. I have 8 of them on my property. Minimum 2" cylinder with a 4" stroke and a tank right at the pump jack works best for me. maybe a 30% - 40% duty cycle on the wind's presence. On hot days you don't get a lot of wind.
The main consideration is what volume of water does it take (say in a given day or week) to supply the number of animals expected. That sizes the machinery along with how much wind do you have over the course of time. No problem with too much water, but not enough is a bad situation.
A conventional, 'vintage' windmill with an 8' wheel is good for about 1-1/2 hp in a strong wind, but has time on its side as far as pumping water volume. I have 8 of them on my property. Minimum 2" cylinder with a 4" stroke and a tank right at the pump jack works best for me. maybe a 30% - 40% duty cycle on the wind's presence. On hot days you don't get a lot of wind.