Reproduction performances and conditions of group-housed non ...

- General discussion -
However, an indicator is not necessarily well suited in an operational context just because
the indicator is possible to perform in commercial herds and well related to the phenomena
under study. Indicators applicable in a management tool should further be meaningful for
the individual farmer (Halberg, 1996). It is e.g. important that the individual manager be-
lieves that an indicator provides useful and relevant information, because otherwise he/she
will not be motivated to use this as a management tool. Furthermore, it is essential that an
indicator is possible to measure or register by farmers or advisors within reasonable time
and costs (Halberg, 1996; Rousing et al., 2001; Sørensen et al., 2001). Whether the two
indicators mentioned above meet these requirements will be discussed in the following.
A systematic investigation of whether the indicators applied were perceived as meaningful
by the farmers, e.g. by means of qualitative interviews (Vaarst, 2003) has not been carried
out. However, none of the farmers or managers questioned the relevance and usability of
the back fat measurements or the observations of eating behaviour at the introductive farm
visits or during the recordings.
Observation of eating behaviour. Time has become a very important issue in pig management,
as the average labour input per animal has decreased (Madsen, 2001; Rasmussen,
2003). The time necessary to observe sows’ eating behaviour was 10 to 25 minutes per
batch as one group of sows were observed per batch and the recordings were carried out
until the last sow had stopped eating or at longest 25 minutes after feeding start. Following
four batches would then acquire between 40 m and 1.7 h plus the time required to select
and mark ten random, focal sows. This seems as a feasible time range in most herds. However,
the disadvantage of manually recording the eating behaviour is that a maximum of ten
focal sows can be overviewed at a time. As a consequence hereof, there is a risk that an
existing problem will not be detected. This problem could, however, be overcome if the
identification of sows with a low feed intake could be automated. O'Connell et al. (2003)
report that low ranking sows visit the drinker more often than the high ranking in a group of
sows and according to own observations it seemed that sows with a very low feed intake
often visited the drinker during feeding. Online registration of pigs’ drinking pattern as an
indicator of e.g. an outbreak of diarrhoea has already been implemented as a commercial
software package, Farm Watch® (Madsen, 2001). Likewise, it might be possible to detect a
feed-related problem in submissive sows by automatical registration of the water consumption
during feeding. In that case, it would probably be possible to identify and pay special
attention to ‘problem sows’ before the reproduction performance was influenced negatively.
Back fat measurements. Assessment of back fat gain from weaning to three weeks after
mating cannot be used for identifying individual sows with a potential reproduction prob-
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