Translation:This is my cow's apple, not Julia's.
I hate it when Julia plods onto my farm and tries to eat my cow's apples. The poor thing is going to starve.
Cows can defend themselves, they don't need the protection of lowly humans ;)
This is now my new absolute favourite Duolingo sentence, overtaking "My horse is not an artist but an architect" (on the Russian tree) !!
That sentence (the artist horse) certainly beats the Spanish learners' favourite, el oso bebe cerveza (the bear drinks beer)!!