2.3. Slaughter and sampling
On days 21 and 42, blood samples were collected by jugular
venipuncture from three piglets (the closest to the mean body weight
in that group) in each treatment group, and subsequently the same
piglets were killed to sample their intestinal tissue and digesta. The
intestines were divided into three parts (duodenum, jejunum, ileum)
according to the method described by Hopwood et al. (2004), washed
with PBS, fixed by immersion in formalin (4%) and stored at 4 °C prior
to analysis of the morphology. The cecum and colon were ligated and
excised fromthe distal end of the jejunumfor collection of their digesta.
The digestawere placed immediately into liquid nitrogen before storage
at −80 °C. Blood samples were collected in vacutainer tubes with or
without anticoagulant (lithium heparin, Greiner Bio-One GmbH), and
centrifuged at 3000×g for 15min at 4°C to separate serum and plasma,
respectively. Plasma and serum samples were stored at −80 °C before
analysis.