Agriculture Reference
In-Depth Information
Bedding should be provided in situations where aggression is likely to take place. Although
bedding does not reduce aggression, it could reduce the risk of leg problems associated
with it (Spoolder
et al.
, 2009). Heinonen
et al.
(2006) found fewer toe lesions among sows
kept on straw or deep litter bedding when compared with sows housed on solid concrete
floors and partially slatted floors. Andersen and Bøe (1999) reported that herds housed
on straw bedding had lower scores for locomotory problems compared with herds housed
on concrete floors. Christensen
et al.
(1995) also reported that straw bedding appeared
to provide protection against gastrointestinal disorders. However, in spite of the positive
aspects that solid flooring can provide to sows, such as providing bedding, it also presents
some disadvantages. These include higher production costs, retention of humidity that
could lead to weakening of the claw horn and the incompatibility between slatted flooring
and liquid manure handling systems (Tuyttens, 2005). Another disadvantage of bedding
is that some bedding substrates like straw could have a negative impact on the hygiene of
the pen and promote the proliferation of disease. For instance, the use of straw bedding in
the resting areas of the pen can increase the possibility of infection with salmonella as the
animals are more likely to be in contact with manure (Alsop, 2005; Davies
et al.
, 1997).
19.7
Disease effects on sow longevity
Studies evaluating the direct effect of diseases on sow longevity are scarce in the scientific
literature. In a study conducted by Sanz
et al.
(2002), it was reported that 18.5% of sows
died due to proliferative enteropathies, 16.6% died due to urinary tract infection (cystitis
and/or pyelonephritis) and 9.2% died due to bronchopneumonia or pleuropneumonia.
However, the authors did not report whether certain parity groups were at higher risk of
death due to these diseases. Pijoan (1986) found that death loss resulting from pneumonia
in adult sows is uncommon, and it accounts for no more than 5% of deaths.
Diseases such as enteropathy, porcine reproductive and respiratory syndrome (PRRS),
pseudorabies (PRS), porcine enterovirus (PEV), swine influenza (H3N2), chronic
erysipelas, acute haemorrhagic ileitis, are just few diseases that have become very common
in sow herds (Loula, 2000; Stalder
et al.
, 2004). These diseases can have a negative impact
on the length of the productive life of sows as some organisms frequently cause sows to
abort and the producers face the decision of whether to cull these females or to retain
them and take a chance on their ability to rebreed. Usually, producers choose to cull these
sows, resulting in a shortened herd life. A more detailed description of diseases that are
important in sow herds is provided in Chapter 18 of the current topic (Friendship and
O'Sullivan, 2015).
19.8
Seasonality effects on sow longevity
Many pork producers observe seasonal variations in reproductive performance of their
sow herd. Peltoniemi
et al.
(1999) reported that rebreeding rate, farrowing rate and age
of gilt at first mating were affected by season irrespective of housing system. However,
Hurtgen and Leman (1980) observed that sows housed in stalls during gestation were
