Farrowing month influenced piglet pre-weaning mortality(Fig. 4). As shown in the figure, piglet pre-weaning mortalityvaried among farrowing months from 11.1% in February to12.3% in October (P < 0.01). The highest percentage of sowswith piglet pre-weaning mortality rates greater than 20% wasobserved in March (Fig. 4). Likewise, the piglet pre-weaningmortality varied among farrowing years from 10.9% in 2008to 13.5% in 2010 (P < 0.001)