Farms differed significantly in sow live weight development (P < 0.05, Table 2) and were therefore analyzed separately. Age and weight at first insemination were 46 days and 21.3 kg lower at farm A compared with farm B. After first farrowing and at first weaning sows on farm A
remained lighter, but the weight difference was reduced from 21.3 kg at first insemination to 9.5 kg at first weaning. Both absolute and relative weight loss during lactation, was
similar for farm A (24.9 kg and 13.6%) and farm B (23.7 kg and 12.3%). On average, sows on farm A gained more weight in the period between first insemination and first weaning
compared with farm B (31.6 kg for farm A, 20.9 kg for farm B; P < 0.05).