In our industry, sow mortality has become a primary focus for producers,
their veterinarians and diagnostic labs.
Only a short time ago, the mortality rates hovered around 5 percent in
nearly all operations.In the past few years, however, the rates have
escalated to unbelievable levels, often exceeding 10 percent for several
weeks to months.
The elevated concern about sow mortality rates started three
years ago, in a hallway at the annual meeting of the American
Association of Swine Veterinarians,when a few veterinarians and
pathologists began discussing what they saw in their practices. This
humble beginning started us on the journey which led to an industrywide
study.
Originally, we focused on the unusual incidence of prolapses,
often both rectal and uterine, in sows. We continue to explore
this issue as a part of the overall research on sow mortality.
Drs. Bob Thompson and Kent Schwartz, along with Emily MahanRiggs,
a student at North Carolina State University, compiled a survey
and provided an “enrollment” sheet to any veterinarian willing
to participate. These professionals filled out the surveys and
submitted samples from problem sows.
You can quickly find several well-written papers on the subject
of sow mortality. In 1991, Drs.Madeleine Chagnon, Sylvie
D’Allaire and R. Drolet published the results of an extensive project
which highlighted some interesting trends.They studied 24 breeding herds
that submitted data on significant numbers of animals.
The herds had an average of 3,755 mated sows and gilts.The producers
agreed to submit information on all dead and morbid sows over a 12-month
period.During this window, the average sow mortality was 3.3 percent. The
figures ranged broadly between operations, though, from the lowest mortality
of 0.0 percent to the highest of 9.2.
In total, participating herds had a total of 137 sow mortalities.
Researchers noted a higher mortality in the months of July, August
and October.Sows appeared to be most at risk during the peripartum
period that is immediately before, during and immediately after farrowing.
During this short time in a sow’s reproductive life, 42.0 percent of all
deaths occurred.The three main reasons for death were heart failure
(31.4 percent), torsions and accidents of abdominal organs (15.3 percent),
and cystitis pyelonephritis (8.0 percent). Minor causes included endometritis,
uterine prolapses,pneumonia and gastric ulcers.
Judging by a review of numerous papers, it seems that
death rates had risen significantly by the mid- to late 1990s. In 1999,
Drs. Christina Irwin, Jer Geiger, and John Deen presented at the North
Carolina Healthy Hog Seminar that “today, 12 to 15 percent (or greater)
sow mortality is seen with more and more frequency.”
Interestingly, the researchers most frequently identified lameness
(muscular-skeletal problems) as the cause of the animal’s demise
(38.2 percent). The locations (either gestation or lactation) where the
animal was housed immediately prior to euthanasia and or death
varied, however.
The researchers identified gastro-intestinal problems as the
second most common cause of death or euthanasia overall (12.9
percent). Again, location varied but was different than for lameness
reasons.
The authors later compiled a meta-analysis of 4 million parity
records between 1996 and 1998, and they found some valuable
insights. The researchers noted a significant increase in sow mortality
within the systems examined. No system seems to have avoided
this trend and the rates were significantly higher than reported in
the literature.
Source : Pigchamp