Influence of various fiber supplements on quantity of microbial biomass in digestive tract of piglets determined by ATP-luciferase assay

Abstract

Dietary fibre has positive effects on digestion and on gastrointestinal tract of pigs. Pigs do not possess indigenous enzymes for its digestion. Fibre is fermented by gastrointestinal microflora. The influence of different fibre sources on quantity of microbial biomass in gastrointestinal tract (GIT) of weaned piglets was studied in our experiment. First we introduced ATP-luciferase assay with pure E. coli culture, mixture of E. coli and somatic cells and samples from small and large intestine. The proper protocol for preparation of samples from GIT for ATP-luciferase assay was established. Twenty four weaned piglets, divided into four groups, were fed the same feed except the included fibre: carboxymethylcellulose (group CMC), lignified cellulose (group LIG) and pure cellulose (group CEL). The control group received starch instead of fibre (group KON). Piglets were sacrificed after 13 days of feeding and digesta samples were taken from: stomach, proximal part of small intestine, distal part of small intestine, caecum, colon and rectum together. The quantity of microorganisms in different parts of GIT was estimated by ATP-luciferase assay. The highest concentration (conc.) of microbial ATP was found in large intestine in all groups. Statistically significant effect of different fibres on conc. of microbial ATP in different parts of GIT was not demonstrated. The experiment did not provide evidence that the soluble dietary fibre (carboxymethylcellulose) would enable more intensive microbial fermentation in weaned pigs than insoluble fiber. The reason was probably in big variability and nonhomogenity of samples from GIT.