I can't help you on sprouting the rye seeds.
But, I have dairy goats and I would love to learn to grow fodder for them.
I did purchase dandelion and sunflower seeds to grow specifically to meet the copper needs of my goats.
I haven't attempted to sprout these seeds as of yet.
I am fascinated with the idea of growing fodder for my goats, and have been purchasing herb seeds with the idea of establishing these to grow in a hedgerow just outside the fence, so they can prune them, but not kill the plants. I have an old book on goat care and they really encourage this for the animals health.
I also purchased some corn that is high protein in the stalks and leaves with the idea of feeding my goats, haven't tried them yet.
When I weed the garden, I take all of the weeds to my goats and they really enjoy helping me to get rid of my problem.
Weeds that they don't care for get to meet the compost pile.
I bought a bag of wheat seeds at the feed store with the idea of sprouting these for the goats, but I haven't tried it yet. I even toy with the idea of attempting to grow a raised bed of various grains, for household use and for feeding the stalks etc to my goats as fodder.
Keep us posted on your successes and failures in this endeavor!
Talk to your plants.... If your plants talk to you... Run!