I'd sprout the corn to substitute for greens.
I ferment a mix of whatever grains I am normally feeding the animals. Just toss it in a bucket, cover it with water with a little to spare on top, and put in a little bit of something with bacteria - whey, yogurt, raw milk, kefir, etc. You actually don't HAVE to have the bacteria, they'll ferment on wild bacteria, it just goes faster and you can control the good bacteria that is in it if you put in your own starter.
You can keep that going for a week or two - ours averages two weeks, just tossing in more and wetting it down in the evening when it gets low, then starting a new batch when we feel like this one might be tending toward being funky (actually it isn't usually, people just respond differently to the smells than animals do, we refresh it just to make sure it stays safe since we are in an area with a LOT of mold spores in the air).
Ferment overnight before feeding it to anything, then just keep it going.
To sprout wheatgrass, just get one of those plant starter trays, without the little pots in it. Fill it with dirt. Sprinkle wheat over the top, sprinkle a little more dirt or perlite, or anything that will help hold the moisture in (or you can use a lid over the top). Soak it completely, and make sure it stays very moist until it sprouts. Let it get 3-4 inches tall, then you can harvest it for up to three or four "haircuts". This works best for people, or to cut up to feed to chicks that are over about a week old, as a treat for rabbits, etc.
You can also sprout wheat in a bucket, which works just as well for animals when you have a lot of them to feed. Toss the wheat in a bucket (I do mine about 1/3 full in a square bucket, which is about how much my animals can use in a few days). Soak it overnight, keeping it completely immersed. Drain it, then rinse it once a day. It will sprout roots, then shoots. You can feed it to animals any time after it sprouts roots, but the more green it has on it, the better it is for them.
Sprout any other grains the same way as the wheat.
Feed the animals fermented grain instead of their regular grain. Feed goats about 1 cup of sprouted corn, oats, or barley as a once a day treat (instead of veggies in the winter), toss sprouted wheat, rye, oats, millet, or corn to chickens, or other poultry.
For alfalfa, either use a sprouter system, or lay down paper towels, dampen them and sprinkle seed on top. Keep the towels wet, and they'll sprout in a few days.