Guide to Carcass Composting

Farmers can always have a refresher course on how to properly dispose of their passed livestock and may also have a chance to learn something new in the process.

During her presentation at Ag Progress Days near Penn State University, Dr. Elizabeth Santini, a state veterinary medical field officer with the Pennsylvania Department of Agriculture Bureau of Animal Health and Diagnostic Services, shows attendees a simple – almost routine – procedure to which most farmers adhere: Composting.

It’s a simple exercise, Santini noted. However, farmers can always have a refresher course on how to properly dispose of their passed livestock and may also have a chance to learn something new in the process. “I tell producers: it’s really not rocket science,” she said. “(Carcass composting) varies from farm to farm. It’s trial and error in the beginning. Once producers try it and they are successful, they are sold. They never go back to what they did before that again.”

Often referred to as something reserved for space in “The Back 40,” composting serves an important purpose for the farm. As part of her work with the state department, Santini helps educate farmers across Pennsylvania on the benefits of carcass composting, such as the curbing of disease and minimizing pestering critters and scavengers.

“Composting is the most environmentally friendly, most economically viable option for producers to deal with animal mortality,” she said. “You can do it with any animal and do it successfully as long as you cover the animal with the right type of materials.”

Materials used

Composting provides a low-cost way of ridding of dead animals. The labor is minimal and can be done with equipment (for example: tractors, shovels, etc.) and materials available on most farms.

“It’s the things that you would find on your farm: sawdust, manure, (I get) wood chips and shavings, old hay,” Santini said. “I like to use a mixture of materials. A mixture of particle size: wood chips, get from local townships to use at the base of the pile. I’ll mix that with dry manure.”

Cover around the carcass at least 2 feet around, literally. “I tell farmers all the time, ‘At the tip of the nose, it should be 2 feet out. From the tip of the tail, 2 feet,’” Santini said. “You don’t want to see a hoof or tail.”

Santini advised that particle size is key for two reasons: the material will have contact with the carcass and the air flow is allowed through the pile.

“The organisms that are doing the composting need oxygen,” she said. “It’s the opposite of packing silage; you want to encourage air flow through the pile.”

The material also provides sustainability in the fact that once the composting process is done, it can be recycled into another pile for another round. The mixture of materials is important to arrive at the right balance for composting. For example, Penn State Extension suggests a rule of hand squeeze test. If you hand squeeze the materials and too much water comes out, it’s too wet and drier material is needed. If the materials crumble and tear apart, then moister material is needed. If it stays in a clump with your hand feeling damp, then the moisture levels are ideal.

Place your animal down: Before starting, make sure the mixture is laid 2 feet around in a float base that is sizeable enough for poultry or an animal of a smaller size. Santini said the mound in total should be no more than 8 feet high.

The perfect pile

Although it’s not difficult to do, composting still requires some guidelines. When choosing a composting site, it should be at least 200 feet from any water source and out of public sight. Once a site is found, it’s time to lay down the base. Santini suggests spreading a 2-foot base on a gradual slope first.

“The most common mistake that people make is putting the carcass directly on the ground,” she said. “The carcass won’t compost because air will not be able to move through the pile from base to the top.”

Santini said the windrow shape works when covering the carcass. “The long shape contains the odor,” she said. “If you don’t have it, the smell gets out and then you will get scavengers on the pile.”

Santini said that although a 2-foot base is recommended, more is always better. The windrow shape – long and slender – allows the water and other moisture to run away from the pile instead of pooling around the base. Once the base is settled, the carcass should placed on top. She recommends covering the livestock with material at a minimum of 2 feet all the way around to ensure proper coverage.

Let the composting begin

Temperature plays a vital role in composting success. If done correctly, the pile will create its own heat. Organisms inside create the heat as they consume the carcass.

“It should reach about 150 to 160 degrees within a week and maintain 120 to 130 degrees if it is working properly,” Santini noted. “You can feel the heat of it on a cold day. Put your hand on it to feel if it’s hot. If it is, then it’s active and it’s doing its job. A composting thermometer is a good investment for composting.”

Santini also noted that farmers can choose to turn the pile within the weeks and months ahead. It tends to help break the carcass up and increase the surface area of the carcass that the material has access to, accelerating the process. Depending on the size of the livestock, many animals – as much as multiple animals at a time – can fit into a pile. The time of composting varies depending on the animal. Poultry takes approximately a couple of weeks, while a regular-sized calf composts in three to four months’ time. An adult cow composts in an 8- to 12-month time frame.

In Pennsylvania, there is a 48-hour window of disposal after the death of an animal. A compliance failure can result in fines up to $300. Santini said when she talks with farmers about their composting needs, it usually turns into a teachable moment.

“For most folks, enforcement is not necessary,” she said. “Once they learn the laws and how to properly compost, they often comply.”

Photos: Pennsylvania Department of Agriculture/Elizabeth Santini, DVM