BROKENSPHERE

Sen. John McCain (R–Ariz.) is back at it, taking swipes at federally funded animal research projects. First he took on the grizzlies—lambasting studies to gauge whether the mighty creatures were in danger of becoming extinct— and now he's peeved about pigs—or pig odor, to be precise. The former presidential candidate last week mocked a federal set-aside for pig odor research, listing it on his Twitter feed as one of the "Top 10 Porkiest Projects" allocated funding in the latest federal spending bill being debated in Congress. Sen. Tom Coburn (R–Okla.) chimed in on his own Web site that "This earmark is $1.7 million to take the stink out of manure," and pretty soon the blogosphere was snorting about liberal (and pig) waste.

Amid threats to strip the $410-billion bill of its earmarks, Democratic Iowa Sen. Tom Harkin took the floor to passionately defend his state's swine scientists. "People constantly complain, with good reason, about big farms, factory farms and their environmental impacts," he said, "so it makes good sense to fund research that addresses how people can live in our small towns and communities, and livestock producers can do the same, and coexist."

The problem with federal earmarks for scientific research is that they can be doled out based on political connections and lobbying rather than on a grant review by a panel of scientific peers. In this case, the Swine Odor and Manure Management Research Unit at the U.S. Department of Agriculture's Agricultural Research Service (ARS) in Ames, Iowa, had been stripped of funding last year by the Bush administration, and this was designed as a way to reboot the program. As Harkin put it, "This item is only included as an earmark now because the last Bush budget proposed to terminate a number of agricultural research projects in order to come in at a lower budget number, knowing full well that this needed research was likely to be restored by Congress."

But what on earth is pig odor research? To find out, we spoke with Jacek Koziel, an agricultural engineer who specializes in livestock odor at Iowa State University and who has helped the ARS team quantify odors for their experiments varying the pig's diet.

[An edited transcript of the interview follows.]

What is pig odor?
We've shown that the odor is a mixture of several hundred different gases, but there are only a handful of gases that really give it the characteristic livestock odor. To me, the top one would be p-cresol. This is a phenolic compound that we've shown is present right at the source—that is, very close to the farm—but it is also one that carries far downwind. Even when you smell it at very dilute concentrations, you would think there are some livestock nearby. Then, there are also a couple other gases that belong to volatile fatty acid groups.

We associate these smells with fecal matter or waste in general. Those aren't necessarily pleasant experiences. On the other hand, you can find similar smells in a number of foods. When the smells are associated with the visual image of cheese or wine or some other food product they aren't necessarily considered offensive.

Why is pig odor a problem?
Typically, pig odor is a localized air quality problem. We usually just have low concentrations of these potent odorous gases such as p-cresol, and those are not necessarily immediately dangerous to our health. However, odor problems are often a starting point for litigation. This is a real problem for many farmers large and small, but small operations in particular can go out of business because of this litigation. This is a real issue to many people. The need to do fundamental research on odor, on controlling odor, and on gaseous dust emissions from livestock is still there. There's no question about it.