The very
low mortality rate observed (on average 2.8%) in the
current study might be explained by both the high birth
vigour score and birth weight of piglets (on average
1455 g). Birth weight has been associated negatively with
mortality rate (Hartsock and Graves, 1976) and survival
rate did not increase in adopted piglets when the birth
score was similar among cross-fostered and biological
litters