Larval survival was approximately three times higher due to the
administration of b-glucan. As the deviation in mortality rates between
the two treatment groups started to occur at around 5 dph,
thus after the first phase of high mortality, we can conclude that
dietary MacroGard® did not affect survival of the larvae during their
first phase of development. Presumably survival in this early phase
could be enhanced by combining larval and maternal immunostimulation
as suggested by Vadstein and demonstrated in
rainbow trout (Oncorhynchus mykiss) by Ghaedi et al. Below
we discuss possible physiological and immunological mechanisms
underlying the enhanced survival rate observed after 5 dph.