Horse Feed

I have a question about horse feed. I am feeding my boy a mixture of maxisoy pellets and pollard, along with vitamin and mineral supplement. Pollard and maxisoy need to be wet/soaked. just wondering if i can mix up both lots of feed at night, so the morning feed can just be fed first thing in the morning, as i start work early and am pressed for time. It is still dark when I leave. Is this safe?