Translations:Breeding/9/en
From Pixelmon Wiki
Once both Pokémon reach maximum affection, they will produce an Egg, which will be visible on the ranch block and can be claimed in the ranch block interface. The Egg will go into the player's party or the player's PC, depending on whether the player's party is full. The two Pokémon that made the Egg will then have their affections reset to 0 and the breeding process will restart.