At The a2 Milk Company, we're on a mission to bring you delicious, nutritious and pure a2 Milk. a2 Milk is naturally occurring cows' milk with added vitamin D. Our milk naturally contains only the A2 protein type (A1 protein free), which may help some people avoid discomfort from milk. We take great care to bring you milk naturally free from the A1 protein from cow to cup. Our cows have not been treated with growth hormones, rBST (No significant difference has been shown between milk from rBST-treated and non rBST-treated cows) or antibiotics