Augmentation of immune development during early life can improve host defense against later life challenges, decreasing the need for antibiotics. To evaluate the effects of pre-weaning immunemodulatory feed interventions on post-weaning gut problems and a later life vaccine challenge, 120 piglets were given one of 5 oral feed interventions, for two weeks before weaning. Post-weaning health was assessed, and 5 weeks after weaning all animals, except the control group, received a double dose of PCV2 vaccination as a challenge. Individual feed intake, health parameters and growth was evaluated. Blood was taken before and after weaning and challenge, for immunophenotyping, serum immune marker assessment and ex-vivo challenges.
All animals showed reduced feed intake shortly after weaning and all animals, except the control group, showed a distinct drop in feed intake after the vaccine challenge, but recovered after one day. One of the interventions showed improved feed efficiency in the fifth week after weaning and reduced rectal temperature six days after the vaccine challenge. The percentage of all innate immune cells and B cells increased during the weaning period with the highest percentages observed just after weaning, but the percentage T cells decreased. No effect on frequencies of immune cells was found after the challenge and no differences were found between the interventions. PCV2 antibodies showed effects of the challenge, but no differences between the interventions. Keyhole limpet hemocyanin (KLH) antibodies (IgM, IgG) also showed no differences between treatments. Data from ex-vivo challenges was not yet available during abstract preparation, but will be presented at the conference.
We conclude that feeding immunemodulatory feed interventions before weaning can have effects on post-weaning performance and health parameters, but effects are not reflected in immune cell frequencies in blood or antibody titers. Final results on ex-vivo challenge experiments will be presented at the conference.