The bacterial population adherent to plant particles in the rumen of reindeer fed lichen, timothy hay or silage

Abstract

Male reindeer (Rangifer tarandus tarandus) calves taken from a natural winter pasture were given ad lib. access to lichen (n = 3), timothy silage (n = 3) and hay (n = 3) for 7 weeks. Median numbers of viable anaerobic bacteria adherent to the plant particles (cells/g wet weight of rumen solids), growing on a habitat simulating medium (M8V), were significantly higher (P = 0.05) in the rumen of reindeer fed lichen (26.5 x 109- 53.0 x 109) and hay (4.0 x 109- 40.5 x 109), compared to reindeer fed silage (1.15 x 109 - 3.25 x 109). Anaerobic bacterial strains (n = 551) from the plant particles obtained from the rumen of the nine reindeer examined, were isolated using an acid swollen cellulose medium (M8SC) and tested for their ability to hydrolyse carboxymethyl cellulose (CMC). The proportion of CMC hydrolysing adherent bacteria isolated from M8SC was significantly higher in reindeer fed hay (21.5%) compared ro animals fed lichen (5.3%) and silage (2.7%) (P = 0.05). The CMC hydrolysing bacterial srrains (n=42) isolated from reindeer fed hay where characterised as non-cellulolytic Butyrivibrio fibrisolvens (9.5%), cellulolytic B. fibrisolvens (50.0%), Clostridium sp. (2.4%) and unknowns (38.1%), while CMC hydrolysing strains (n=11) isolated from animals fed lichen and strains (n=4) isolated from animals fed silage where all characterised as B. fibrisolvens. None of the bacterial strains isolated from the rumen solids of reindeer fed lichen or silage were found to be cellulolytic. This study suggests that both lichen and timothy silage have a negative influence, compared to hay, on the numbers of cellulolytic bacteria adherent to the plant particles in the rumen of reindeer

Ecology of Uncultivated Oscillospira Species in the Rumen of Cattle, Sheep, and Reindeer as Assessed by Microscopy and Molecular Approaches

“…An ecological analysis (Table 1) confirmed that the high counts of the large morphologically conspicuous form of Oscillospira, termed O. guilliermondii, were recorded in Orkney sheep consuming seaweed diets (2.5 ϫ 10 7 per g of ingesta) and in Svalbard reindeer on summer pasture (7 ϫ 10 6 per g of ingesta) (20,21). The results from the present study show that consistently high counts were obtained from the rumen of reindeer in northern Norway and Svalbard (1 ϫ 10 7 to 5 ϫ 10 7 per g of ingesta).…”

“…For subsequent confocal microscopy, a Fluoview FV300 laser-scanning biological microscope (version 3.00; Olympus, New York, N.Y.) was used. Transmission electron micrographs (TEMs) were obtained from rumen content of reindeer by using the methods described by Olsen and Mathiesen (20).…”

Ruminal Fermentation and Fill Change with Season in an Arctic Grazer: Responses to Hyperphagia and Hypophagia in Muskoxen (Ovibos moschatus)

“…High rates of in situ degradation during hyperphagia are probably not a simple outcome of increased microbial counts in muskoxen even though more bacteria could increase rates of colonization on food residues and shorten the lag time in beginning digestion of substrates (Spalinger et al 1986;Ellis et al 1999). Induction of attachment systems may be crucial in switching to unusual forages such as lichens (Olsen and Mathiesen 1998), but seasonal differences in those delays are probably small when diet changes are small as it was for our studies of captive muskoxen.…”

Monitoring digestibility of forages for herbivores: a new application for an old approach

“…: 0.56 ± 0.08 g/g). Studies of lichen digestion in reindeer suggest that digestion may be achieved by microbial enzymes that are induced after a period of acclimatization (Olsen and Mathiesen 1998;Storeheier et al 2002). We did not acclimate our study animals to lichens before measuring the digestibility of these feeds in sacco, therefore, in sacco lichen DM digestibility estimates were much lower than those estimates measured by others for animals acclimated to lichen (e.g., 0.37 ± 0.13 g/g for the greygreen reindeer lichen (Cladina rangiferina (L.) Nyl.…”

“…Digestibility of DM was probably similar between in vivo and in sacco methods because they both use microbial communities to break down the majority of DM in feeds. These microbes are very efficient in DM digestion for a number of reasons: microbes are present in diverse assemblages (Dehority 2003), able to secrete a wide range of enzymes (Dehority 2003), can penetrate the fiber matrix (Dehority 2003), and can shift enzyme production to match substrates of ingested feeds (Olsen and Mathiesen 1998). In addition, both in vivo and in sacco digestibility methods take advantage of intra-animal conditions optimized for extensive digestion where proportions of endogenous enzymes, substrates, and reaction products are continually being adjusted to maximize reaction speeds.…”