KALAMAZOO, MI -- New, hungry workers on Western Michigan University's campus have drawn a union grievance.

After a half-acre trial run in 2016, Western Michigan University hired a team of goats this summer to clear 15 woodland acres on campus.

Goats consume three to five pounds of vegetation per day, according to rental company Munchers on Hooves LLC, and they leave behind natural fertilizer.

But the natural mowers have not impressed everyone.

A statement written in a newsletter indicates a grievance was filed relating to the to subcontracting and the use of goats.

WMU Horticulturist Nicholas Gooch said the language provided to him came from the July 17, 2017, Chief Steward Report newsletter, written by Kathi Babbit, American Federation of State, County and Municipal Employees local 1668 chief steward.

"I also filed a grievance as it relates to subcontracting and the use of goats which was not reported to the Local and again, we have people on layoff," a copy of the newsletter Gooch provided to the Kalamazoo Gazette reads.

Calls placed and messages left for union officials were not returned this week.

"Afscme At Wmu," a Facebook page, in June posted a link to a news story about the goats on campus, and mentioned nine employees out of work.

WMU Spokeswoman Cheryl Roland said "No WMU workers have been displaced by the goat project."

Roland said it's not appropriate for her to make any detailed comment because WMU has a process underway for addressing the grievance.

The goats are a chemical-free option to clear the areas that are problems for humans to remove, she said.

"...we chose the goat solution to stay environmentally friendly," she said.

The school's analysis showed the goats to be a sustainable and cost-effective way of removing poison ivy and invasive species, she said.

Gina Fickle, co-owner of Coldwater-based Munchers on Hooves, said the goats are helping address areas that haven't been worked in years.

"This stuff is so thick," she said, and can be a safety issue for people. After the goats do their work to clear up to five feet above the ground, then human laborers can come in to finish the work, she said.

"Goats aren't there taking work away from anybody, they're making it safer for people," she said.

Gooch said WMU has not received other complaints about the goats, and that the effort has been going "as close to perfect as possible."

"We have been very happy with the progress, impact and PR generated from this project from both the campus community and the community as a whole," he said. "There have been no complaints of any nature prior to the news of this union ordeal."

Support for the project continues to be strong and almost seems to be gaining momentum, he said.

Business is booming, Fickle said, and people are ordering shirts from around the country as their story spreads to national news outlets.

The goats are scheduled to be around on campus until about a week before fall classes begin, and they are there eating vegetation this week, Roland said.