Continued selection for reproduction and leanness,
without increasing lactation feed intake, will likely result
in a larger proportion of young sows consuming
an insufficient amount of feed to adequately support
lactation (Cameron et al., 2002). Inadequate intake will
lead to increased losses of backfat and BW, probably
resulting in more culling of sows due to reproductive
failures and a reduced lifetime performance (Eissen et
al., 2000). Inadequate feed intake during lactation is
particularly evident in primiparous sows because, relative
to multiparous sows, they have smaller body reserves,
a lower daily feed intake, and need extra energy
for BW gain (NRC, 1987).