Litter size of Danish crossbred sows increased without changes in sow body dimensions over a thirteen year period

The purpose of this study was to investigate if body dimensions of Danish crossbred sows (Yorkshire x Landrace) had increased compared to a previous Danish study from 2004. In addition, and as an expected potential benefit of increased body dimensions, a potential correlation between body dimensions and litter size was also investigated. Depth, width, length and height were measured from 405 Danish crossbred sows in 10 different herds, classified in groups of parity 1, 2, 3, 4, 5, 6 and ≥ 7. By Linear Mixed-Effects Models with depth, width, length and height in turn as response variable and parity and herd as explanatory variables, estimated means, 5th and 95th percentiles, minimum and maximum observation were recorded. Furthermore, a weighted index for litter size (denoted as the “litter size potential”) was used as response variable with depth, width, length, height and parity as explanatory variables in an additive linear model. The factors were removed individually and in combination to test the effect. Mean depth, width, length and height were estimated to 66, 43, 192 and 90 cm, respectively, for full grown sows (parity ≥ 5). Sows' body dimensions were not found to have increased since 2004. The result of this study did not find significant (P < .05) effect of sow dimensions on litter size.