Effects of concentrate proportion in the diet with or withoutFusariumtoxin-contaminated triticale on ruminal fermentation and the structural diversity of rumen microbial communitiesin vitro

Abstract

The objective of this study was to investigate the effects of the concentrate proportion and Fusarium toxin-contaminated triticale (FCT) in the diet on nutrient degradation, microbial protein synthesis and structure of the microbial community, utilising a rumen simulation technique and single-strand conformation polymorphism (SSCP) profiles based on PCR-amplified small subunit ribosomal RNA genes. Four diets containing 60% or 30% concentrates on a dry matter basis with or without FCT were incubated. The fermentation of nutrients and microbial protein synthesis was measured. On the last day of incubation, microbial mass was obtained from the vessel liquid, DNA was extracted and PCR-primers targeting archaea, fibrobacter, clostridia, bifidobacteria, bacillii, fungi, and bacteria were applied to separately study the individual taxonomic groups with SSCP. The concentrate proportion affected the fermentation and the microbial community, but not the efficiency of microbial protein synthesis. Neither the fermentation of organic matter nor the synthesis and composition of microbial protein was affected by FCT. The fermentation of detergent fibre fractions was lower in diets containing FCT compared to diets with uncontaminated triticale. Except for the clostridia group, none of the microbial groups were affected by presence of FCT. In conclusion, our results give no indication that the supplementation of FCT up to a deoxynivalenol concentration in the diet of 5 mg per kg dry matter affects the fermentation of organic matter and microbial protein synthesis. These findings are independent of the concentrate level in the diets. A change in the microbial community composition of the genus Clostridia may be the reason for a reduction in the cellulolytic activity.

Microbial ecology of the rumen evaluated by 454 GS FLX pyrosequencing is affected by starch and oil supplementation of diets

“…() in cattle receiving very high concentrate diets, but was found in the study of Boguhn et al . () in the rumen of dairy cows with diets that were similar to ours. The addition of starch increased the abundance of Bifidobacterium and Olsenella genera but decreased that of Atopobium genus.…”

Modulation of Intestinal Functions Following Mycotoxin Ingestion: Meta-Analysis of Published Experiments in Animals

“…The tolerance of ruminants to some mycotoxins is attributed to toxin metabolism by rumen microorganisms, the detoxifying potential of the rumen may be influenced by diet composition. Indeed, the intake of a diet low in structural and high in rapidly degradable carbohydrates will decrease rumen pH, and an acid pH has been demonstrated to inhibit the complete transformation of DON to its metabolites [47]. Using different concentrate proportions in ruminant rations, realistic doses of DON decreased the fermentation of fiber fractions at the lower pH value [47,48] indicating a restriction of cellulolytic microbes.…”

“…Indeed, the intake of a diet low in structural and high in rapidly degradable carbohydrates will decrease rumen pH, and an acid pH has been demonstrated to inhibit the complete transformation of DON to its metabolites [47]. Using different concentrate proportions in ruminant rations, realistic doses of DON decreased the fermentation of fiber fractions at the lower pH value [47,48] indicating a restriction of cellulolytic microbes. The change in the microbial community of the genus Clostridium , which contains cellulolytic species, after inclusion of DON confirmed these findings [47].…”

“…Using different concentrate proportions in ruminant rations, realistic doses of DON decreased the fermentation of fiber fractions at the lower pH value [47,48] indicating a restriction of cellulolytic microbes. The change in the microbial community of the genus Clostridium , which contains cellulolytic species, after inclusion of DON confirmed these findings [47]. As reviewed by Maresca and Fantini [97], mycotoxins might be potential risk factors for chronic intestinal inflammatory diseases.…”

Development of nucleic acid based techniques and possibilities of their application to rumen microbial ecology research

“…Therefore, a combination of the classical microbiology with advanced molecular methods can increase our understanding of processes occurring within the rumen. The advantage of molecular techniques is lack of microorganisms cultivation and analysis of samples taken directly from the rumen (Tajima et al, 2001) or the multicultural in vitro culture (Bekele et al, 2010;Boguhn et al, 2010).…”