fraction that provided 80% of the amount of IgG in the
SDPP diet. In Exp. 3, there was no response to SDPP
during the first week, but a positive growth response
to SDPP (P < 0.01) occurred by the end of wk 2 (0 to
14 d). Feeding the IgG-rich fraction increased growth
rate compared with controls (P < 0.05). Over the entire
experiment, the greatest ADG occurred with the IgGrich
fraction that provided 128% of the amount of IgG
provided by SDPP (quadratic; P < 0.05). Two additional
experiments assessed feeding SDBP and bovine IgGrich
fractions to early weaned pigs. In Exp. 4, SDPP
was superior to SDBP in stimulating growth and feed
intake, but this difference did not occur in Exp. 5. In
both experiments, the IgG fraction of bovine plasma
seemed to be as effective at improving growth as SDPP
and more effective than SDBP. The results indicate
that both porcine and bovine plasma are beneficial to
young pig performance during the first week after
weaning and that the IgG fraction of plasma is the
component that is responsible for the enhancement in
growth rate and feed intake.