Agriculture Reference
In-Depth Information
19. Sow longevity
J.A. Calderón Díaz
1
, M.T. Nikkilä
2
and K. Stalder
1
1
Iowa State University, Animal Science, 109 Kildee Hall, Ames, IA 50011-3150, USA;
2
Figen Ltd., Urheilutie 6 D, 01370 Vantaa, Finland
Abstract
Poor sow longevity in commercial breeding herds can lead to economic inefficiency and
animal welfare concerns. Reproducing females are the most valuable animals in the herd
and it is estimated that 40 to 50% of sows are culled before their third or fourth parity,
a time at which initial replacement costs have not been met. The reasons for culling
sows and the rate of removal may be influenced by many factors including housing,
genotype, management, disease, nutrition and market trends. Regardless of the cause,
poor longevity results in larger replacement rates and, consequently, larger gilt pools
which translates into higher production cost. Gilts are less productive than sows; their
offspring have greater mortality, reduced growth rate, and poorer feed efficiency in the
nursery and grow-finish phases of production. Additionally, there is a disease risk when
new animals are introduced into the breeding herd. An improvement in longevity can
result in decreased replacement costs and production cost and a greater proportion of
mature sows in a herd that have reached their maximum productivity.
Keywords:
culling, longevity, parity distribution, herd productivity
19.1
Introduction
Sow longevity is a key component for efficient and profitable pig farming; however, the
sow culling rate has steadily increased which suggests that breeding herd sow longevity
has declined in recent years. A high percentage of sows in commercial breeding herds
are replaced after producing only one or two litters, a time at which the sows have not yet
reached their maximum productivity and their replacement costs have not been recovered
(Carroll, 2011; Stalder
et al.
, 2003). High removal rates are a concern for pig producers
as it impacts farm profitability and production efficiency. Additionally, high removal
rates may present animal welfare concerns since some culling and mortality causes could
indicate that an animal(s) might be experiencing comprised animal welfare (Barnett
et
al.
, 2001). Additionally, poor longevity resulting from high culling and mortality rates can
impact the consumer's perception about the pig industry and the consumer's acceptability
of modern pig production practices and pork products.
Approximately 70% of sow removals are the result of premature and unplanned culling
due to reasons like reproductive failure and leg problems (Engblom
et al.
, 2011). In the
USA, approximately 54% of breeding sows are removed (i.e. culling plus mortality rate)
