Hello,

Perhaps Jan will see this or Rudy, but If I had to guess this is a horizontal bracing truss (note the iron rods) that is meant to stiffen the valley and gable wall connection. I would would note also, that this is "transitional balloon framing" from the more vernacular and classic timber framing systems that you can find in older barns of Iowa. This barn presents as circa date 1890 to 1930, or contemporary replica of the same time period.

Hope that helps,

jay