“Mortalities” are the “industry” euphemism for dead animals. To compost “mortalities” is to compost animals that have died on the farm. So far, 2009 has been a big year for dead animals on this farm and I hope I don’t have another year like it for a long time. In late winter, my favorite goat Izzy died due to a management mistake, then the ewe The Old Girl died of OPP (I think), then two feeder pigs died from a vicious bacterial infection. All four animals went into a compost windrow, although, in retrospect, I probably should have burned the pigs to ensure that I killed the bacteria.
For the past couple of months I have been putting off turning the compost windrows because I was worried about what I would find. I finally did it yesterday. As I came down the windrow, the first animal I encountered was Izzy, who has been in the windrow the longest. When I put her in, however, it was cold and the windrow was not cooking well. Left of Izzy were bits of bone and fur and a strong unpleasant odor that unfortunately continuously blew into my face because I was facing into the breeze. To increase the rate of composting, I mixed a couple bucket fulls of nearly finished compost in with what remained of Izzy’s body and then covered it back up.
About twenty feet further down the line I found The Old Girl. Her body has been in the pile since May 17. There was nothing left of her but a mat of wool and a hunk of malodorous pink slime. When I had originally placed The Old Girl’s body in the windrow, I had surrounded her with a couple buckets full of nearly finished compost, which I believe explains the difference in the rate of composting between her body and that of Izzy. I mixed in some more nearly finished compost.
A bit further down the line I came across the first feeder pig, which has been in the windrow since about the first of June. Bits of bone and that malodorous pink slime. The next feeder pig was in about the same condition.
I didn’t have my compost thermometer with me, but the compost in the area around the pigs was really cooking. When I opened the windrow up quite a bit of steam billowed out.
Basically what I discovered yesterday is that in two to three months — in a static pile — a 150 pound animal will be nearly completely composted. What I have read about composting larger animals like cows and horses is that it takes three to four months is a windrow that is cooking well.
Composting is by far the best option for getting rid of animal carcasses, as long as it is done correctly. If it is not done correctly, it is a foul putrid mess. More and more agricultural experts are counseling large animal farmers to compost bodies rather than bury them, burn them, or drop them out on the back forty for the buzzards. Composting binds up and then makes available the nutrients contained in the animal tissues, and a pile that is cooking well enough will kill off most pathogens. Basically you end up with a more or less inert soil amendment.