Investors who sold Chinese dairy companies after tainted formula killed at least six infants three years ago are buying again.

Yili dropped 67 percent in 2008 in Shanghai trading after it was identified among 22 companies that sold products containing melamine. The stock of China's top publicly traded baby formula maker has jumped more than fivefold since then, and 21 out of 22 analysts tracked by Bloomberg who cover the stock predict it will continue to rise. The Shanghai Composite Index has gained 33 percent since the end of 2008.

China Mengniu Dairy Co., the country's biggest listed milk producer, lost 65 percent of its market value in 2008. Its stock has since more than doubled. Mengniu gained 1 percent to HK$26.35 in Hong Kong trading today, while the benchmark Hang Seng Index slid 1.4 percent.

"The dragon year baby boom is almost a sure thing, which will boost the demand for infant products such as baby formula, diapers and clothes," said Michele Mak, a consumer-sector analyst at BNP Paribas.

China introduced a one-child policy in 1979 to curb population growth and drive prosperity. Now, facing an aging labor force, the government has eased restrictions by allowing couples who are both only children to have two kids of their own. In addition, rural couples whose first child is a girl over four years old are allowed a second child.

Eoin Treacy's view In the list I posted on Friday of companies that derive at least 20% of their revenue from Asia and/or Latin America a number with exposure to Asian population growth were evident.

Mead Johnson Nutrition yields 1.55% and its fastest growing unit is China, which now accounts for more than 20% of revenues. The share has been trending steadily higher since being spun off by Bristol Myer Squibb in 2009. A break of the progression of rising reaction lows, currently near $65 would be required to question medium-term scope for additional upside.

Bristol Myer Squibb has only been providing region specific data since last year. The share hit a new 9-year high three weeks ago and has been unwinding the overbought condition relative to the 200-day MA since. It will need to find support in the region of the trend mean to indicate a return to demand dominance.

Perrigo's Outside-US revenue is growing faster than its domestic market. The share has returned to test the area of the 200-day MA where demand will need to reassert itself if the advance is to remain consistent.

Heinz' Asia Pacific revenue is also its fastest growing by region. The share has also returned to test the 200-day MA and will need to find support in this area if the medium-term bullish outlook is to be sustained.

Nestle is a European dividend aristocrat and yields 3.59%. It has been labouring under the strong Swiss Franc and broke downwards from the 18-month range in August. The share pushed back up into the overhead range and is testing the region of the 200-day MA. A sustained move back above CHF52.50 would suggest a return to demand dominance beyond the short term.