I had to stay in the hospital one week with my newborn (she is 4 weeks now) and I was pumping to increase my milk supply. While there the nurses told me I could not store breast milk that had been nippled on in the bottle because the saliva gets mixed in and makes it unsafe. I was very disappointed when I had to throw away 2 ounces. Since then I use 1 ounce at a time and it gets aggravating making several trips to the kitchen to warm up additional milk. However I have read that breast milk has antibiotic properties and was wondering if I actually have to throw out a bottle of milk that has been nippled on?