Hello Cem, and welcome to the forum! I have visited Turkey 3 times, and it is a beautiful country. Unfortunately I have never been in the region of Düzce - someday I would like visit in that area as well.
You definitely need to reach a pH of around 5.3-5.4 in order to make mozzarella. The cheese will not stretch properly (or at all) except at that very specific pH. To get that pH, you need either to ripen (ferment) using lactic acid bacteria, OR you can try adding acid directly to get to the right level (citric acid is typically used). One thing I need to say is that mozzarella is actually one of the more difficult cheeses to make, because of the very narrow range of pH that must be achieved.
The abomasum may contain some lactic acid bacteria, but I would not count on it; it is mostly for the rennet which causes the milk to turn into curd. If your milk is raw, it will definitely contain various bacteria, including lactic acid bacteria, but generally you want to help boost the right type of bacteria. Here is an easy solution - yogurt. Mix some yogurt up with some of the milk, and add it back to the rest of the milk. Give it some time at around 30-32°C to begin to develop before adding the rennet (abomasum).
I am not sure if I am answering your questions. Please ask more questions as needed!