Every day, a gigantic, rotating steel cylinder situated between two huge Colorado hog farms turns thousands of pounds of mortalities into compost.

It's an outside service Alliance Farms, Yuma, CO, has been using about six months. Operation's support manager Ron Swehla estimates an annual savings of $56,000.

Composting carcasses eliminates a 120-mile round trip to the rendering plant, the two-plus hours of labor for the driver, and, it spares the public the disturbing sight of seeing deads going down the highway, says Swehla.

Mortalities from Alliance Farms and Central Plains Farms, a Smithfield subsidiary, are hauled to a biosecure site owned by Ace Composting, which grinds them up with a mixture of crop residues and cattle manure and adds the material to the revolving drum.

The end product looks and smells like silage, notes Roc Rutledge, who manages Ace Composting, the family owned business with his father, Don, and brother, Brett. A modified, vertical feed grinder with a 100-hp motor handles everything from afterbirth to full-size sows.

Farrow-to-finish mortalities from Central Plains, and losses from Alliance Farms, a sow-to-feeder pig operation farrowing 20,000-plus head annually, are delivered between noon and 1 p.m. to Ace's automatic scales. Trucks from each farm have a separate entrance secured by electronic gate and separate scales. A computer printout gives Roc the pounds delivered and from that he builds a ration-like mixture for the grinder.

Ace charges the farms pennies per pound, just like a renderer, without the long-distance hauling expense. Mortalities average 16,000 lb. a day.

The composter is a 10 × 60 ft. open tube built on a downward slope. Every day about 30,000 lb. of material is added and 30,000 lb. is removed. The cylinder rotates a complete turn every 15 minutes and maintains an internal temperature of 130 to 145° F.

It takes about three days for the organic matter to work its way to the far end of the tube, explains Rutledge. When the cylinder revolves, material tumbles out through large, opened doors onto a conveyor, which dumps the compost into a concrete pit. Here, the remains “cook” another 15 days at 140 to 150° F. At the end of that stage, Rutledge spreads the composted material in windrows to dry before adding it to a large pile.

The entire process takes 63 days. The end product is 6 to 7% organic matter and the Rutledge's spread it on their sandy fields.

Swehla is more than pleased with the arrangement. Alliance Farms was considering building its own composting site as an alternative to rendering, a business he feels is becoming obsolete in Colorado. But the licensing requirements and cost of the carbon source were prohibitive.

Alliance gained prior experience with composting two years ago through a pilot project with the Governor's Office of Energy. Wood chips from forest restoration were blended with placentas and baby pig mortalities to make an environmentally safe fertilizer. The project was mentioned in the Sept. 15 issue of National Hog Farmer, which featured Alliance Farms' units #102 and #103 as 2002 Environmental Stewards award winners.

“Once it was finished, we knew composting was the way to go,” Swehla recalls. “Taking material back to the soil for crop production makes the whole circle work. The nutrients go right back to the land.”

Rutledge figures the $350,000 commercial composter will pay for itself in 10 years, but not without a few gray hairs. “Everything we have is test material and there have been mechanical failures. We've had problems with the grinder, conveyors and the composter. It's a new venture for us, too, and it's a learning process. We've never handled compost before in this volume.”