Perhaps the hottest debate topic in the pork industry this winter has been the extent of PRRS-driven death losses. There is really nothing new about that statement. It could have been made each of the past 10, 15, perhaps 20 years. This disease and its amazing and depressing ability to mutate and gain new levels of virulence has defied many, many good minds and undermined some very good planning and efforts. To say the least, it has been a challenge.
But will it impact the market this year? Producers always think it will. “PRRS has killed every pig in southern Minnesota so we will run out of pigs in June!” – or something along those lines – is the gist of the claims. Of course, porcine reproductive and respiratory syndrome (PRRS) has not killed every pig in any geographic area and, in fact, may not be any worse from one year to the next. There is a background level of death loss that the market has become accustomed to and, unless we experience something significantly worse than this “normal” level, we will never see a supply or price impact.
This is not a new phenomenon. There was a time not so long ago that we had this discussion around Transmissible gastroenteritis (TGE) every year. I have not raised pigs in the PRRS era, but I did in the TGE era and on occasion it was no fun. That characteristic smell of an infected farrowing house – wet, slimy pigs and dead pigs could be just about too much to take on some days. But those “killed every pig in Iowa” scenarios never showed up in supply data because they, too, were “normal.” They didn’t even show up as TGE waned (I think due to confinement barns and much better bird control), because it was a gradual process.
This may be the year I am proven wrong but my experience – and that of my mentors, Professors Glenn Grimes and Ron Plain from the University of Missouri – is that, though it seems worse than ever, we will not see these losses in the form of abnormally lower supplies this summer. Here is why:
None of this is meant to minimize in any way the awful situations that some producers have found themselves in this winter. It is chilling to hear an Ohio producer say that he lost 15% of his SOWS to PRRS. And I know there are other stories like that. But even this year’s weaned and feeder pigs markets (see Figure 1) are only slightly higher than last year’s and are about the same as 2005 and, in the case of weaned pigs, 2006. There is little evidence that abnormally short supplies caused blow-out tops in the summers of those years.

But there is one issue that could cause a downward supply shock yet this spring: last summer’s heat. There was nothing gradual about it. It hit virtually everyone at the same time and, in spite of our sophisticated buildings, artificial insemination, tight management, etc. had reportedly a significant impact on conception rates. Those should have shown up in late September-November and early December-February farrowings, but USDA’s numbers do not fit with the anecdotal evidence. September-November farrowings were up 0.45% from 2011 and December-February farrowing intentions were up 0.77% from one year ago. Those are from a December 1 breeding herd that was 0.4% larger than in 2011.
If the anecdotal accounts are correct, we could see a drop in weekly slaughter from the forecast rates in late April. One analyst colleague told me he had April 20 marked on his calendar. I have it a bit later than that but not much. It appears we will put my “sudden event” vs. “gradual event” theories to a test.

