A tutorial on a new abm design. It's resource friendly, uses almost nothing but wood and water :). You don't have to use glass for the tubes, it's just for the clear view.
If you have more than 2 animals at a time in the breeding bay, use more fence gates (bottlenecks) and connect these with the redstone of the other fence gates. Do not unequip your wheat while breeding, if you do so the baby animal won't jump out. If you didn't breed the animals and you want to send them back, UN-equip your wheat before doing so.