Chinese dairy giant China Mengniu Dairy Co. just got bigger. It has entered into an agreement that will see it take control of local infant formula maker Yashili. Mengniu is looking to reverse its fortunes in a category in which it has struggled. However, with concerns over food safety remaining high, there is a long road ahead as the company - and the country as a whole - look to build a safe and reliable dairy supply. Katy Askew reports.