You may use chain link fencing of 3mm thickness and eight feet height with a mesh size of 4"X4" with an additional cover of Fishnet upto 4' height from out side to protect against dogs / predators attacking the birds when they peep out. This reduces the cost compared to using a 2"X2" chain link net.
For Goats you may use the similar material of 4 - 4'6" height.
You may contact the local converters / makers of chain link fencing.
