Ecology of Lactobacillus in the gastrointestinal tract of the weanling piglet

To investigate the effects of weaning and weaning diet on the ecology of adherent Lactobacillus species in the gastrointestinal tract sixteen piglets were used. At 28 d of age four pigs were killed and served as the pre-weaning control (PW). Four pigs remained on the sow (Sow), four pigs were fed a corn-soy-lactose (CSL) diet and the remaining four pigs were fed a corn-soy (CS) diet. Pigs from the latter three treatments were killed at 38 d of age. Total lactic acid bacteria were isolated from the pars esophagus, ileum, and cecum. The highest numbers (P $<$.05) of lactic acid organisms were isolated from the pars esophagus $(1.66\times10\sp{-9}$ CFU g$\sp{-1})$ and ileum $(1.36\times10\sp{-9}$ CFU g$\sp{-1})$ of animals receiving the CSL and CS diets. Selected bacterial pure cultures were speciated using classical techniques and typed by using restriction fragment length polymorphisms (RFLP) in conjunction with a 23S rRNA gene probe. Data was analyzed using Shannon, Simpson and, evenness diversity indices. The biotype and RFLP data was subjected to cluster analysis, and the clusters were defined as operational taxonomic units (OTU). The phenotypically typed bacteria, and data based on OTU were used as the basis for the calculation of Shannon, Simpson, and evenness indices as well as for a comparison of lactobacilli composition (based on phenotype and OTU) between treatment groups. The Shannon index indicated that the diversity of lactobacilli were the most similar when the PW and Sow treatments were compared for the pars esophagus (1.61 and 1.24 respectively) and ileum (1.04 and 1.04 respectively). The Simpson index confirmed the Shannon index. A comparison among the treatment groups indicated that the physical form of the diet (sows milk vs a dry diet) was an important factor in determining the composition of lactobacilli (phenotype and OTU) in different gastrointestinal compartments.U of I OnlyETDs are only available to UIUC Users without author permissio