By Jill Dunn

Kenworth Truck Co. will lay off 450 temporary employees at its Chillicothe, Ohio, plant who were hired six months ago.The workers were hired to deal with an industry wide upswing in orders as customers rushed to buy trucks with engines built before October’s new federal emission standards.Their last day will be Oct. 25. Truck production will decrease from 70 to 45 trucks daily, said plant manger Alan Mayne. About 1,100 workers will remain at the plant after that day, he said.The Chillicothe plant celebrated production of its 200,000 truck this year.