MUSCATINE, Iowa — The Mars Petcare plant in Muscatine is closing its doors immediately and 47 workers will be without jobs.

Company officials say that the Muscatine location is among several sites that do not have the design or capability to be part of the company vision.

Mars Petcare, formerly Doane Pet Care at 4901 59th Ave. W., is a manufacturer of such name brands as Pedigree, Cesar, Whiskas, Sheba and Nutro.

Four other sites will also be affected, including those in Birmingham, Ala.; McKenzie, Tenn.; and Butler and Dexter, Mo.

Mars started with 29 plants of differing age, design and capabilities.

“It’s clear that we are operating in a rapidly changing environment, with increased focus on raw material integrity and finished product quality across the entire pet food industry,” Debra Fair, a spokeswoman for the New Jersey-based company, said Wednesday in a statement.

“We aspire to be the leader in addressing these challenges, and therefore must accelerate the implementation of our vision,” Fair said.

Mars recently built a Center of Excellence for Analytical Science in Kansas City, Mo., to serve as the central testing laboratory for raw materials and finished goods. This site will be equipped with state-of-the-art testing instruments and processes. The current lab facility in Joplin, Mo., will close in mid-2009.

In recent months, Mars has invested tens of millions of dollars in plant upgrades, new testing protocols and advanced associate training in order to achieve the company vision.

The company said it will assist all affected workers as they make the transition to new careers.