Pig-Powered Composting:

Livestock can help manage manure on your farm

By Christopher Shirley
The New Farm, Sept/Oct 1994, p. 53-55, 60

Joe Salatin designed this cattle feeder to rise as wood chip bedding and manure accumulate.
SWOOPE, Va. – Perennial innovator Joel Salatin has added yet another enterprise to his family's Polyface Farm: hogs that turn his compost. "Piggery composting make windrow composting obsolete," says Salatin.

Eight pigs help keep nutrients cycling efficiently on the 550-acre farm by rooting in compost piles of cattle manure, wood chips and hay in early spring." Pigs love it. If you hide some fermented grain in a pile, they'll completely invert and aerate it by the time they're through. So you handle a pile once, instead of two or more times with mechanical turning methods," says Salatin, who started using porcine processors in '93.

"The beauty of this is the pigs are doing almost all the work," he notes. "And the result is an excellent finished product."

Salatin's inspiration came in '92 when he saw a picture of a pig on a pile of horse-manure bedding. "Something clicked, and I went and tried it with two pigs last year. It worked so well and we got such good money for great-tasting pork that we added more hogs this year and built a second pen," he says.

Natural nutrients, by design

The Salatins' 50-cow beef herd generates more than 2,500 pounds of nutrient-rich droppings daily. From early April through late December, the cattle fertilize pastures directly", with some help from a flock of cowpie-crazed chickens. (See "Profit by Appointment Only," The New Farm, Sept./Oct. '91.)

In winter, the bovines munch homegrown hay in an open-sided shed from V-shaped rising feeder gates that Joel designed. With added bedding, the feeders help prevent muddy loafing areas, minimize nutrient loss and virtually eliminate scrape-and-haul time.

"Deep bedding provides a clean, fresh place for the cows to lounge. It has hygienic and economic benefits beyond labor savings. We find that they consume 10 to 15 percent less hay to maintain body condition than they would require in a mud yard," says Salatin.

Rooting for buried grain, eight pigs penned on the bedding piles helped make 70 tons of compost this year.

He fashioned the feeders so he could raise them as the manure packs build up. Hooked to four barn poles spaced 15 feet apart, each 45-foot feeder accommodates up to 23 cattle at a time. Four angle-iron struts at a 20-degree angle below horizontal serve as upper arms that tip a feeder forward and help position cows so they waste less feed. Quarter-inch chains–one per pole–support each feeder near the bottom of the poles.

The top and bottom of the feeders include a 3-inch-diameter metal pipe with a 3-inch-wide flat bar welded beside it. That provides lateral buttressing and allows lag-screw fastening of the 2x4 wooden "V" slots for feeding. To keep eager cattle from bending in the pipes by pressing too hard against a feeder, Salatin wired a wooden stump to serve as a bow truss behind the pipes.

"The chains hold most of the feeder's weight but don't have to hold it against the cows pushing and pulling. That's borne by the struts on the top along with the bow truss," says Salatin.

Metal brackets on the posts secure the top struts and bottom chains and allow Salatin to raise the feeder 4 feet above ground level. He lifts an entire feeder using a front-end loader. He usually moves the feeder up a notch at a time–about 7 inches–as the bedding piles up!

Sweeten the pot

Salatin adds absorbent wood chips from tree trimmings to the bedding, every two to three days with a manure spreader. He also adds some straw and old hay about every four days. The mixture saves 75 percent of the excrement's value, he estimates. "The high-carbon bedding acts as a stable 'nutrient sponge' that eliminates leaching, vaporization and odor, while giving the cows a comfortable lounging area." (See "Chip Tips," p. 55.)

After feeding hay for 90 to 100 days, Salatin turns the herd onto pasture, pens the two bedding areas and brings on the pigs. "Prepping the piggery is winter work. Then the pigs do the composting during our busy spring season," he notes.

Chip Tips

For a ready source of superb bedding material, Joel Salatin makes green wood chips from his managed woodland, using an industrial-grade wood chipper. With his 2-ton dumptruck with 1.5-cubic-yard bed, 4-wheel-drive pickup truck, lowboy trailer and front-end loader, he also hauls in material from local horse stables, the city leaf dump and municipal tree-trimming stockpiles.
"After Christmas, I go in and park at the municipal chipper and they blow all the Christmas tree chips right into the truck, says Salatin. He also pays a tree-trimming crew from nearby Staunton $10 per truckload to dump at the farm, and purchases rain-damaged hay and straw.
Green chips eure quickly when piled in the barn and soon reach a point where they'll absorb 150 percent of their weight in moisture. "You want good water-retentive ability, so they capture urine well, and tie up nutrients," he explains.
By not turning the stockpile, you encourage anaerobic growth of some molds and fungal threads on buried wood chips, which in turn make natural "probiotic" antibodies that help prevent mastitis and scours, he says. Spread beneath cattle feeders in winter with some hay and straw, the enriched-chip bedding starts composting nicely on its own, Salatin has found. Composting then kills many pathogens and weed seeds, while stabilizing soluble nutrients. The chips also work well in poultry houses, rabbitries and brooders.
For health and safety reasons, be sure your storage area is well-ventilated and that you use a dust mask when handling particulate material such as wood chips, Salatin cautions. Woodchip piles can generate a high internal temperature, especially during summer months. So check your stockpile regularly to be sure it's not getting too hot. To minimize fire hazard, some forest specialists suggest limiting pile height to 2 feet or less, especially in dry months.
"There's plenty of carbonaceous material available. You just need to be creative about finding it rather than letting it go to waste," -C.S.

During winter as the bedding accumulates, Salatin "seeds" it with 100 pounds of barley, rye, oats or corn every few days so eight pigs will have plenty of buried treasure to dig for. A pair of hogs will turn 75 cubic yards of enriched bedding in eight weeks looking for 1,000 pounds of grain, he's found. Even though he figures the pigs won't find at least 100 pounds of the grain, Salatin says he's supplying less grain than the industry norm of about 10 pounds per day. "With fermented grain, I only need to supply about 9 pounds per pig per day."

The grain heats up and gets soft and tasty. "The pigs will dig four feet to get the grain–so low that all you'll see are their tails at times." The pigs gain anywhere from 10 to 12 pounds per week, depending on their starting condition.

Last year he learned not to put corn at the bottom of the pile but to start with a small grain, such as barley or rye. "The extra husk protects the inner kernel. It's 'first in, last out' for the grain. So you'd lose some corn if it's on the bottom," he says.

Buckets gravity feed nipple waterers in each pen. But because all the grain is fermented, the pigs need very little water. "If they were eating dry grain they would triple their water consumption," says Salatin, who occasionally adds some fresh hay, grass and garden clippings to the pens.

'The best breed for rooting is Tamworth, a long-snouted minor breed, says Salatin. "But they're expensive. My neighbor helped us pick up some common pigs at a sale auction barn." The pigs were about 5 months old, weighing about 170 pounds each. "We de-ringed them so they could root."

If using more than a pair of pigs, you need to beware cave-ins and "free-loading" once rooting holes reach depths of 30 inches or more, he cautions. "Pigs will go down a couple feet or so just great on their own. But then one might start doing all the work while the rest are content to freeload off existing holes and take the dribbles." The surface pigs then cause cave-ins. "I had to dig back down to the mother lode a number of times this year when too much compost got between the pigs and the goodies."

If your bedding pile is less than about 3 feet high, you probably won't have a problem regardless of pig numbers, he figures. Next year, Salatin will put a temporary gate across the middle of each pen and put just two pigs per side to minimize cave-ins.
After their pen work, pigs either go on pasture or right to slaughter, depending on their size and the cattle schedule. "They're already sold. It's up to me to decide when to have them dressed," says Salatin.

He feeds shelled corn free-choice while the pigs are on pasture. "But they only eat 5 pounds of corn per day. They prefer the pasture–you ought to see them eat that grass."

Salatin spreads the piggery-compost–about 70 tons worth in '94–on pasture that has been grazed once and just hayed. The finely textured, pig-turned compost has a fresh, earthy smell you wouldn't associate with conventional hog production. 'We feed the soil when the grass wants to regrow. That helps boost pasture growth during slump periods," says Salatin.

From cattle manure, tree trimmings and crop residue to rich pastures, healthy livestock and wholesome meat products, "piggery composting helps everything just fall into place."