The world's biggest infant formula maker Nestle is launching its own brand of A2-only baby formula in Australia and New Zealand as it looks to muscle in on the dominant position of high-growth stock, The a2 Milk Company.

While many dairy makers have held back from selling products that only have the A2 beta-casein protein, perhaps sceptical about its benefits and cautious of undermining their regular milk sales, a2 Milk has proved to be a huge growth story. Revenue has surged from $NZ62.5 million in 2011-12 to $NZ923 million in 2017-18. The company's market capitalisation has swelled to more than $7 billion.