At birth bacterial co- lonization may affect organ and intestinal functions in neonatal mammals and this may be strongly related to mother’s milk and feed consumed after birth. The aim of the present study was to evaluate the effect of preterm feeding in piglets with milk formula or sow’s colostrum in a germ-free or conventional environment and compare its impact on organ and gastrointestinal development.

For the experiment 38 piglets were obtained f rom 3 sows delivering via caesarean at day 106 of gestation. From each sow, foetuses from a single uterine horn were assigned to a germ- free isolator (GF) after passed through a 1% sodium hypoclorite submersion, whereas foetuses f rom the second horn were assigned to a conventional infant incubator (CV) and fed either sterile infant milk formula (CV- FORM, GF-FORM) or sow’s colostrum (CV-COL, GF-COL). Piglets were fitted with an orogastric tube to be used for enteral feeding (15ml/kg BW/ 3h) for 40-48h. After 48h, animals were euthanized in order to take samples of the gastrointestinal tract sections (stomach, small intestine and colon). Heart, spleen, liver, kidneys, pancreas, lungs, the empty stomach, small intestine and colon were weighed. Histological examinations of different section of small intestine were conducted. Oral and faecal swabs were taken and cultured.

Results from histological examinations from CV-FORM showed short, stunted villous while from GF-FORM and CV-COL showed long, fingerlike villous. Pigs from GF group had a higher mucosal small intestine proportions and a higher relative weights of pancreas and small intestine sections. Pigs fed colostrum showed higher mucosal small intestine proportions, spleen and lung weights. Colostrum fed piglets and germ- free animals were similar although stomach, pancreas and distal small intestine weights were higher for germ-free piglets.

It is concluded that colostrum had an important role o n gastrointestinal tract and organ development during the neonatal period. The initiall bacteria colonization interacts with diet to modulate the early neonatal organ development.