The effect of timothy silage on the bacterial population in rumen fluid of reindeer (Rangifer tarandus tarandus) from natural summer and winter pasture

Abstract

The seasonal effect of first cut (FC) and regrowth (RG) timothy (Phleum pratense) silage on the rumen fluid bacterial population and the ability of this microbial ecosystem to digest cellulose was compared to that of reindeer from natural pasture (NP). FC with 27% leaves contained 30.4% dry matter (DM) cellulose and 6.2% DM water soluble carbohydrates (WSC), while RG with 89% leaves contained 18.4% DM cellulose and 30.0% DM WSC. The number of culturable anaerobic bacteria per ml rumen fluid on a habitat simulating medium (M8V) ranged between 1.1×108 and 95.0×108 in the reindeer (n=18) investigated, and no significant (P>0.05) differences were found between animals from NP and animals from the experimental groups in summer or winter. Carboxymethyl cellulose hydrolysing bacterial strains (n=138) isolated from the rumen fluid of the animals (n=18) using an acid‐swollen cellulose medium were characterised as Butyrivibrio spp. (69.6%), Eubacterium spp. (1.4%), Clostridium sp. (0.7%) and unknowns (28.3%). Cellulolytic strains of B. fibrisolvens were isolated from only one of the calves, which had been fed RG in summer. The rumen bacterial composition in reindeer on NP resembled that of the experimental groups. In vitro digestibility trials demonstrates that the ability of the rumen microbiota to digest cellulose is generally reduced in reindeer fed silage in summer compared to winter. Ruminal malfunction occurred in some of the animals, but no correlation between the composition of the bacterial population in the fluid fraction of the rumen and the ability of this microbiota to ferment cellulose was found.

Rumen function in reindeer (<em>Rangifer tarandus tarandus</em>) after sub-maintenance feed intake and subsequent feeding

“…The total number of culturable bacteria (TC) seems not to have been affected by the different feeding regimens, except for slightly lower counts for the PS group. The observed counts were similar to what has previously been reported for free-living and silage-fed reindeer (Aagnes et al, 1995;Olsen et al, 1997).…”

“…When the experiment started, the rumen function of the reindeer seemed to be representative of animals on good winter pasture, as shown by pH, total VFA, molar proportions of individual acids and counts of TC bacteria corresponding with levels measured in freeliving reindeer grazing on natural forage in winter (Åhman & Åhman, 1980;Aagnes et al, 1995;Olsen et al, 1997;Mathiesen et al, 2000b). A normal winter condition in the reindeer at the experimental start was confirmed also by the values obtained for different blood metabolites .…”

Diversity of a stable enrichment culture which is useful for silage inoculant and its succession in alfalfa silage

“…Silage inoculants are expected to control microbial events during silage fermentation. Although numerous studies had been carried out on the analysis of the microbial events during the ensiling progress, the techniques used were mostly conventional cultivation methods (Jones et al , 1991; Charmley et al , 1996; Gourama & Bullerman, 1997; Olsen et al , 1997; Driehuis et al , 1999; Driehuis & Wikselaar, 2000; Bach et al , 2002; Flythe & Russell, 2004); it was laborious and time‐consuming to monitor population dynamics. Novel molecular approaches, especially those based on the use of rRNA and rRNA gene, have provided the opportunity to analyze complex communities on the basis of sequence diversity (Amann et al , 1995).…”

VARIATION IN THE RUSSIAN ARCTIC REINDEER (Rangifer tarandus) RUMEN MICROBIOME RELATED TO SEASON CHANGE

“…Olsen с соавт. (20) на основе классических микробиологических методов, продемонстрировали снижение общего количества микроорганизмов в рубце северных оленей Rangifer tarandus platyrhynchus в зимний период по сравнению с летним на порядок. Аналогичные результаты по снижению в зимний период численности жизнеспособных зооспор хитридиомицетов описаны также для других видов жвачных (21,22).…”