Have multiple tribe mates from different regions so that someone is always on to get milk (by trapping wyvern in a cage) and feed it to any wyverns raising. There are many different trap designs on YouTube but you need a rectangular built cage with a behemoth gate on one end and a dinosaur gate on the other end (both made of at least stone). You will use electrical parts to install a keypad on the dinosaur gate end of the trap. Now you you will need something fast to lead a wild wyvern into the trap. Argy at 200 movement will work. Assign the behemoth gate a pin and match it to the key pad. Lead a wyvern through the cage and fly out the dino gate and deactivate the keypad with the pin set on the behemoth. Now you have a wyvern trapped. Tranq it and take the milk to preserving bin. Now you have milk. Note: You can transfer your wyvern egg to the island or center and hatch it there and just transfer back and forth with the milk in your inventory. The spoilage time is increased.
I got a level 150 lightning egg and I was so excited to hatch the egg...that when I went to put the egg down I accidentally ate it instead. :( ps4 users: R2 ISN'T GONNA DROP THE EGG YOU'RE GONNA EAT IT LIKE ANY OTHER EGG. REMEMBER THIS. LOGIC BEFORE EXCITMENT.