Okay as far as milk goes you can use barrels. They last a couple of days. Better way an ice wyvryn. They are refrigerators. There are always people giving them away. The milk will last 4 days. It will keep anything perishable and add more time to decay timers. Portable refrigerators. Doesn't matter what level. They can hold a large amount. You want to maybe invest in some bison. Not only do they feed wyvryns it will advance their growth by 10 percent it's really cool. So if the cute wyv asks for wyv milk give it bison milk and watch it grow in front of your eyes. You can use bison milk throughout the growing process. If you are good on a wyv find an alpha kill it and you will receive 50 wyv milk for doing so. Make sure your inv is not Blackboxed on wyv. You will need to find bag if so on ground. And for your own mortality make sure your wyv has stamina on it. My wyvs have no less than 3500 stam and 20000 health and 1500 plus melee. That took me a min to do and can be done with much lower stats. Just a pain to run out of stamina. I fight in air clear out rhe cave and take on 15 wyvs at a time. Just takes practice. It's do able don't give up cause you will die many times. Gl out there