seen in EXP 2 was because intestinal samples should
be taken even earlier than d 21, such as around d 3 or 7
when the intestinal morphology is undergoing dramatic
growth and change. Another possibility could be that
because of the compound’s solubility, it might not be as
available early in the chick’s life, when feed intake is the
lowest and retention time in the gastrointestinal tract
is shorter. Smith et al. (2012) suggested that the maximum
time for extended release of butyric acid from a
MicroPEARL, which uses the same encapsulation technology
that is used to manufacture ButiPEARL, was
approximately 4 h. Again, Hu and Guo (2007) showed
an improvement in BW gain in the starter phase but
not through to the end of the trial. This may be because
the sodium butyrate they fed was more readily available
to the young chick but was not protected enough to be
available in the small intestine as the digesta retention
time increased.
In conclusion, the results of this research indicate
that the highest BW gain and most improved feed conversion
can be achieved with supplementation of up
to 500 g of an encapsulated source of butyric acid
per ton and that further research needs to investigate
under relatively unchallenged conditions the effects
of butyric acid on intestinal morphology prior to
21 d of age.