Deere & Co. is laying off 57 workers at its Davenport manufacturing plant, saying reduced building activity is expected to lower sales of the construction and forestry equipment made there by as much as 15% next fiscal year.  The Moline, Illinois-based company said it notified employees at its Davenport Works of the cuts about a week ago. The cuts become effective Jan. 6.  It's the second round of layoffs the company has announced this fall. In late September, Deere said it was laying off 113 employees at the Davenport plant, effective Nov ...