支持E。这里过去分词应该没有歧义,至少不比现在分词更歧义(cows provide and milk?)。而且E比A简洁,A里providing them..., milking them...,them重复太多次。
For the farmer who takes care to keep them cool, provided with high-energy feed, and milked regularly, Holstein cows will produce an average of 2,275 gallons of milk each per year.
等于
Provided with high-energy feed, and milked regularly, Holstein cows will produce an average of 2,275 gallons of milk each per year for the farmer who takes care to keep them cool.