A typology according to weaning to first service interval in sow herds

This study provides recent informations about weaning to first service interval (WSI) variability in French sow herds. Analysis is based on 2004-2006 sow records, which were extracted from the national GTTT databank, for 999 herds. Reproduction criteria were calculated at herd level, and data were submited to PCA and clustering analysis in order to characterize different WSI herd profiles. Average WSI lasted 6.1 ± 1.2 d., with more than 90% herds mating more than 80% sows within 6 days after weaning. Delayed (7-22 d.) or extended (>23 d.) WSI, occured in almost all herds on average for 7.8 and 3 % of the sows respectively.Between herds variability was important with 25% of them performing delayed matings at least for 10% sows, and 3% of herds with more than 10% extended WSI. Four distinct herd profiles aroused from the typology. Besides the average A group (70% herds), the B group (20% herds) was associated to lowest WSI criteria. The D group (6%) was associated to highest rates of reproduction troubles (low fertility, delayed (18.1%) and extended (3.4%) WSI), poor weaning results and shorter lactations than expected. Herds from C group (4% ) had large sizes, high fertility and prolificacy but exhibited high rate of delayed oestrus (12%) and irregular (24-38 d.) returns (36.1 %), with frequent early weanings and litter management procedures. Further investigation is required to identify management factors involved in high rates of delayed post weaning matings.