Steve,
SIAF stated that they are building one farm and then 4. Therefore one would expect no construction on the 4 until management saw positive results from the trial. I expect this to be as early as three months out and as long as 6 months out. As a result, the 4 subsequent farms won't be constructed until 1Q 2012. There is a learning curve for SIAF, even with its expertise, so expect there to be some issues with the trial farm, which could delay some or all of the 4 subsequent farms. Consequently, revenue for the 4 farms won't show up until 2013 if at all. Finally, the next 8 farms I wouldn't expect to get built until 2H 2012 at the earliest.
it is possible that the trial farm is so successful that the batch of 8 moves up to a time closer to the 4. If SIAF is purchasing supplies for 4 or all 12 of the farms up front, then completion times are likely to be shorter but that runs the risk of a large sunk cost of there are problems with this farm.
China's environment is significantly different than in Australia, where these were developed, so it's impossible to be sure how well these insulated environments will translate. I expect that they will but possibly with some modification, which increases initial time and costs.
Cheers