I am following this also. Mine are almost 12 weeks old. I let them out a few weeks back thinking they would go back into there coop that evening. WRONG! I was out after dark trying to drive them back into their coop. I do have 3 adults that are free range and I feed them right beside the little...
We never had twins but I have heard that they would be sterile. I hope that I was some help but I am by no means a professional. Please let me know if it helps.
I don't know which is higher. We fed Sudan hay which we grew but I know alfalfa is much better. You should check around and see which is most cost efficient. Roled corn should not be expensive.
We have had cattle most of my life. They do look under weight. I would get them some good hay like alfalfa and increase their feed up to a gallon or more each twice a day. You would have to increase it slowly. You can use sweet feed and you can add roled corn. Good grass to graze is great but...