The breed of most of your cows is Angus. You can create a custom field with a list of just the breeds you own and tick the Repeat box on that field's settings screen. Once you select and enter Angus on the Weigh screen, each new animal you add after that will default to Angus. If you have a cow that is a different breed, you can still select its breed from the list. After that the field will repeat the newly selected breed.