Characterization and reproductive performance of swine females submitted to manual obstetric intervention

The aim of this study was to determine the characteristics of farrowings with manual intervention and to evaluate the effect of this intervention on the subsequent reproductive performance and culling rate. Data of 4121 farrowings were separated in Control (3271 farrowings) and Intervention (850 farrowings) groups. The percentage of farrowings submitted to manual intervention was 20.6%. There was no difference (P>0.05) in the occurrence of intervention according to litter size classes (<11, 11-14 and >14 piglets). The proportion of intervention at parturition increased (P<0.05) during summer and in higher parity order (PO) females. In farrowings with intervention there were longer farrowing duration in PO 1 females (P<0.05) and greater number of stillborn piglets and higher frequency of farrowings with at least one stillborn (P<0.05) in PO 1, PO 3-5 and PO 6-10 females. In the Intervention group, greater weaning to estrus interval (WEI), lower farrowing rate and lower subsequent total born piglets (P<0.05) were observed in PO 1 and 2, PO 3-5 and PO 6-10, respectively. Removal rate before first insemination post weaning, by both reproductive and non reproductive reasons, was greater (P<0.05) in Intervention group. Manual intervention at parturition is more frequent during summer and among older females. Manual obstetric intervention compromise the WEI, the farrowing rate or the subsequent litter size.

parturition; removal of females; reproduction; season; stillbirth