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Team Promotes Composting of Dead Animals

9/15/2012 7:00 AM
By Dick Wanner Reporter

EAST EARL, Pa. — A busload of professionals with an interest in dead farm animals spent the morning of Aug. 30 in a meeting room at the Shady Maple Smorgasbord looking at slides of dead cows, chickens, hogs and horses.

Then, they had lunch.

This group had paid scant attention to the yuck factor of the morning’s presentations. They focused instead on the economic, environmental, aesthetic and political impacts of on-farm mortalities, an inevitable life-and-death consequence of farming with animals.

“Where there is livestock, there is deadstock,” has become one of ag’s newest catch phrases.

There was a time when rendering companies would not only pick up dead animals, but also pay for the privilege. But economic factors such as dramatically lower prices for hides forced them to first stop paying for carcasses, and then to charge for picking them up.

That rendered rendering unaffordable for farmers.

Although the ag community bemoans the loss of the rendering option, the people who advise farmers have given up beating that dead horse.

There were about 60 of those advisers gathered at Shady Maple to talk about alternatives. The one that stood out was on-farm composting.

In the afternoon, they visited three Lancaster County farms where composting has become the preferred way to deal with mortalities.

Most of the people at the daylong workshop hailed from Extension, conservation districts, NRCS, USDA and APHIS, although there were a few farmers in attendance.

Workshop leaders included Pennsylvania Extension educators Craig Williams and Gregory Martin. Also presenting were Jean Bonhotal, director of the Cornell Waste Management Institute, at Cornell University, Ithaca, N.Y., and Mark Hutchinson, an Extension professor at the University of Maine.

Hutchinson is also a director of the Maine Compost School, the country’s oldest and, by many accounts, the most highly regarded source of composting guidance and training.

Bonhotal, Hutchinson, Martin and Williams make up the Northeast SARE Carcass Management Team. The USDA’s Sustainable Agriculture Research and Education program funds much of the team’s research and outreach.

Bonhotal started the morning’s presentations with a discussion of mortality disposal methods. Burial, digestion, incineration and landfill are all options, but they’re not ideal, she said.

Buried carcasses can pollute groundwater, and if they’re too shallow they can attract scavengers. Incineration is expensive.

Shredding dead animals so they’ll work in a methane digester is a possibility, she said. But a shredder is a capital expense, takes a lot of power to run and a strong stomach to watch.

It’s the rare landfill that will accept dead animals, and the ones that do charge a hefty tipping fee.

Bonhotal said there are businesses that collect dead animals from farmers, but they charge sometimes substantial fees.

That leaves composting, and Bonhotal is a strong advocate of on-farm composting, properly done.

Currently, she favors static, passively aerated piles for individual animals, or windrows for multiple deads.

Turning can speed the composting process, but it requires labor and fuel, and it releases odors. A properly constructed and sited pile or windrow draws air from the bottom, providing oxygen for the heat-producing organisms naturally present in the carcass and the high-carbon materials surrounding it.

Air moving through compost can actually create “chimneys” from the bottom of the pile to the top, where outgoing air is rich in carbon dioxide.

A pile in the act of becoming compost — it takes two to six months — quickly heats to 140-160 degrees Fahrenheit, which kills the pathogens in the carcass and the material surrounding it.

Bonhotal and her fellow presenters repeatedly stressed the importance of airflow through the composting material.

Like composting itself, the science of composting is a work in progress. Experiments by farmers and researchers are encouraged and welcomed, no matter what the outcome.

For one experiment that Bonhotal tried during her 20-plus-year career with Cornell’s Waste Management Institute, she inserted pipes in the bottom of compost piles to increase airflow. So many flies crawled into the pipes that the test was abandoned.

After Bonhotal’s presentation, Williams talked about siting a composting facility and told the group about his work with farmers looking for help in locating their compost operations.

High and dry is best, he said. A level spot with a permeable surface that can be scraped without too much damage is important, as is easy tractor access.

A leachate catch basin or filter strips for runoff are necessary, and there is debate within the composting community about whether or not a roof is needed.

Hutchinson — who, before he arrived at the workshop, was described by one audience member as “the god of composting” — talked about his research and work with farmers.

He said he believes that composting is absolutely the best way to deal with mortalities. And while the science of composting is complex and constantly evolving, the practical aspects are understandable and easy to apply.

A compost pile or windrow should have 25-30 parts carbon to one part nitrogen, which comes primarily from the dead animal.

A 2-foot layer of wood shavings, corn fodder or other porous material — to allow for airflow — should go under the animal, followed by 2 more feet of material on all sides and on top. Easy enough, perhaps, but Hutchinson showed slides of many piles with protruding bones and pictures of dogs digging into piles.

Properly constructed, Hutchinson said, a compost pile won’t give even a hint of what’s inside to dogs, coyotes, skunks or turkeys.

In the afternoon, the group boarded a bus and toured three nearby farms that were composting their dead.

The first stop was the Earl Ray Zimmerman farm in Ephrata. Zimmerman raises 62,000 broilers at a time, checks his houses daily and puts dead birds in a solid concrete stall with three closed sides and one open side.

He piles the birds in the stall, occasionally adds fresh litter from the broiler and leaves the pile alone. The chickens gradually disappear. It’s a good system, Hutchinson said, but the concrete walls limit air movement.

Next stop on the tour was the Brecknock Orchard in Mohnton. The family-run 65-acre farm consists of an orchard, a popular farm market and two broiler houses.

Darryl Martin, who owns and operates the farm with family help, said that a few weeks before the tour visited his farm, he installed a Rotoposter composting drum designed to handle his dead birds, which he had been stockpiling.

Although he had been using the machine, he said not enough time had elapsed for him to get any in-depth operating experience.

Martin said he likes the machine’s small footprint and the fact he can operate it at times when he has no customers wandering around the farm, which has a considerable pick-your-own business.

The last stop was at a hog buying station owned by the Rotoposter developer, Kurt Good, who owns Good’s Livestock Inc. in Denver, Pa.

The Brecknock Orchard Rotoposter is the smallest of 10 models available. With a 5-foot diameter and 16-foot length, it can handle 1,000 pounds of dead chickens a week.

The Rotoposter at Good’s Livestock is the firm’s biggest. With a 10-foot diameter and 40-foot length, it can handle up to 10,000 pounds of mortalities a week and turns dead hogs into partially cured compost in about two weeks.

Hutchinson said the material coming from the Rotoposter needs to sit for a month or two before it’s completely cured, but that it can be field applied any time.

Hutchinson said that in his many years of composting work, he has never made claims about the soil nutrient value of composted animals. But, he said, the material is an excellent soil amendment.

Six weeks before the tour, Good made three composting piles outside the shed housing his Rotoposter. One pile held a 450-pound boar, one had two hogs with a combined weight of 450 pounds, and one held a 450 pound sow.

The piles were constructed according to the guidelines developed by the composting team, although each pile used a different recipe of composting materials.

On the day of the tour, Good opened all three piles. There were a few bones, some bits of hair and a small slab of flesh, but otherwise almost no evidence that each pile had once contained nearly a quarter ton of pork.

After the tour, Ken Naples, who’d made the trip to Lancaster County from his farm in New York’s Finger Lakes region, said he’d learned a few things that would help him deal with his own mortalities.

Naples and his wife, Rosemary, raise replacement heifers.

“It would cost us $3,000 or $4,000 a year to have somebody come in and take our dead calves away,” he said. “Composting works if you’re careful, and it doesn’t take that much time.”

For more information on composting, visit http://cwmi.css.cornell.edu. Good can be reached at rotaryposters.com. Williams is at jcw17@psu.edu, Martin at gpm10@psu.edu and Hutchinson at mhutch@maine.edu.

Dick Wanner can be reached at rwanner.eph@lnpnews.com or 717-419-4703.


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