Second parity sows often have lower pregnancy rates or smaller litter sizes compared to first parity sows, the so called second litter syndrome (SLS). In a retrospective study we investigated factors associated with the SLS, based on measures of sow development and reproduction data from two experimental farms in The Netherlands. Data were analysed using logistic regression. Two binary outcome variables were defined: non-pregnancy (NP) and ‘at least one piglets less in second parity compared to first parity’ (RTB, as total number born). Repeat breeders were excluded from the analysis on RTB, as they often have larger litter sizes compared to nonrepeat breeders, which can mask the SLS. Prevalence of NP was 11% for farm A and 15% for farm B. Prevalence of RTB was 31% for farm A and 45% for farm B. Data analysis showed that growth of first parity sows is of large influence on pregnancy rates and litter sizes of second parity sows. Every 10 kg weight gain from first breeding to first weaning decreased the chance on NP (Odds Ratio (OR) = 0.7 for farm A and 0.6 for farm B) and on RTB (OR = 0.7 for farm A). This indicates that a farmer should pay extra attention to management of young sows in order to optimize reproduction efficiency of second parity sows. Litter size from first insemination in cycle provides more accurate information on production results compared to litter size from total inseminations and should be included in sow management systems.
|Title of host publication||Proceedings of the 12th Annual Conference of the European Society for Domestic Animal Reproduction, Utrecht, The Netherlands, 20 - 23 September, 2008|
|Publication status||Published - 2008|
|Event||Annual Conference of the European Society for Domestic Animal Reproduction - |
Duration: 20 Nov 2008 → 23 Nov 2008
|Conference||Annual Conference of the European Society for Domestic Animal Reproduction|
|Period||20/11/08 → 23/11/08|