The short and sicuro, cassetta di sicurezza answer? Listen to the cow.
The other answer? Smell it and look at it, and it also depends whether o not its been opened. I'd say no about drinking the milk- chuck it away, its not sicuro, cassetta di sicurezza for any person o pet to drink. One giorno te could get away with, two no.
That depends on the latte acutually. 'Sell da Date' is the governments doing, which states the law requires the negozio to sell the products da this data before they reduce and try and get rid. Two days after reducing and the product is still there and it must be thrown as waste. 'Best da Date' is the manufacturers law, that is put on each product as a GUIDLINE ONLY! Plenty of products, such as cheese, milk, meat, eggs etc can last for a full week AFTER the BBD before going bad. But that depends on storage, how te handle the product (say if te keep your eggs in the fridge and need to sposta them everytime to get something at the back etc).
But with anything te buy, fresh/frozen etc must be carefully tested and tried before and after the best da date. I'd say give it a sniff see if it smells like cream o stronger then normal and if so take a teaspoon, pour a small amount onto the teaspoon and just touch your tongue to the liquid. If it tastes a little funny then i'd say that's a definate no and to chuck it. But if it tastes okay then i'd say go for it. But like i said, best da data and sell da dates are laws from the government and guidlines only. In England, the government is actually planning on getting rid of the best da dates as that is a huge factor in Cibo going to waste that could have been eaten.