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

- Conclusions -
6. CONCLUSIONS
Two review papers revealed a good theoretical and experimental background for believing
that individual variations in feed intake, social stress and fear could be contributing reasons
for impaired reproduction seen in some group housed sows. The results of a detailed farm
study including 14 commercial herds, supported the assumption that group housing in practice
may lead to individual variation in feed intake severe enough to impair pregnancy rate
and perhaps also litter size, as correlations between back fat gain and reproduction performance
as well as between eating time and reproduction performance were found. As a
consequence hereof, back fat measurements and observations of the eating behaviour of the
sows might be useful components in a decision-support tool to analyse and improve the
reproduction performance in group housed sows. No convincing correlations were found
between chance of pregnancy and litter size on one side and the indicators of social stress
and fear on the other. Since stress and fear are difficult to measure, this does not necessarily
demonstrate that no relations exist between reproduction and these characteristics. It does,
however, indicate that the indicators applied are unsuitable to reflect the reproduction performance
of group housed sows under practical conditions.
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