SimonSkafar/Getty ImagesTwo batches of raw milk from a trendy California brand have tested positive for bird flu this week.Bird flu has been spreading rapidly among cattle in the US.Experts say drinking raw milk is dangerous, and can cause food poisoning.Another batch of raw milk just tested positive for bird flu in California.Last Sunday, Fresno-based Raw Farm voluntarily recalled a first batch of cream top whole raw milk with a "best by" date of November 27.