I grew up milking cows and drinking raw milk as well. The reason we didn’t get sick was because of the basic quality control we did as routine. In order for the pathogens to cause illness it needs three things: innoculum, time to grow and the right temperature to grow at.
The milk was immediately put into the fridge when we brought it in. It stayed in the fridge until it was used.
When you have 1-2 gallons coming into the house every day, you use a lot of milk and use it constantly. You don’t put a gallon in the fridge and drink over 2-3 weeks. You have to consume, process or dump it because the fridge only holds so much and you only have so many jugs. We made butter and cheese every week at least. No gallon lasted in the fridge more than 5-6 days. Usually it was used in 2-3 days.
We knew the cow well. When she was sick or had an infection, we dumped the milk. We had to give ours antibiotics for mastitis a few times. We dumped the milk until the antibiotic was out of her system as well.
Any jug that smelled off was dumped. It wasn’t a big deal since we had another gallon coming in a few hours.
Yah, you always milked off the first bit on the ground or to the cats. We sold a little bit to the dairy so we didn’t end up wasting a lot, and everything went to the fridge quickly. On the other hand, I loved milk and on a hot day I’ve drank the better part of a gallon by myself so there wasn’t much chance of it laying around. I did stop doing that when I realized how god-awful many calories whole milk has in it.