Repeated inoculation of cattle rumen with bison rumen contents alters the rumen microbiome and improves nitrogen digestibility in cattle

Abstract

Future growth in demand for meat and milk, and the socioeconomic and environmental challenges that farmers face, represent a “grand challenge for humanity”. Improving the digestibility of crop residues such as straw could enhance the sustainability of ruminant production systems. Here, we investigated if transfer of rumen contents from bison to cattle could alter the rumen microbiome and enhance total tract digestibility of a barley straw-based diet. Beef heifers were adapted to the diet for 28 days prior to the experiment. After 46 days, ~70 percent of rumen contents were removed from each heifer and replaced with mixed rumen contents collected immediately after slaughter from 32 bison. This procedure was repeated 14 days later. Intake, chewing activity, total tract digestibility, ruminal passage rate, ruminal fermentation, and the bacterial and protozoal communities were examined before the first and after the second transfer. Overall, inoculation with bison rumen contents successfully altered the cattle rumen microbiome and metabolism, and increased protein digestibility and nitrogen retention, but did not alter fiber digestibility.

Invited review: Application of meta-omics to understand the dynamic nature of the rumen microbiome and how it responds to diet in ruminants

“…Both of these studies included a total mixed ration (TMR) containing significant levels of concentrate so it would be interesting to examine whether this relationship holds in cattle fed a diet with high forage and little to no concentrate. We recently conducted a study with cattle fed a 70% barley straw diet and observed apparent neutral detergent fibre digestibility ranging from 42.2% to 61.1% (Ribeiro et al, 2017). Fibre digestibility in this study was highly correlated with Metadinium protozoa.…”

“…The observed increase in Fibrobacteriaceae was suggested to be due to an increased level of lignocellulose in the diet from the addition of straw (3% of diet DM) to the diet. This hypothesis is supported by Ribeiro et al (2017) who found that Fibrobacteraceae accounted for 25% of the OTUs in rumen solids from heifers fed a 70% barley straw diet. In other studies, Fibrobacteriaceae were only a minor component in cattle fed TMR diets indicating that variability between animals likely exists (Callaway et al, 2010;Zened et al, 2013).…”

“…Prevotella sp. have been noted to be ubiquitous in the rumen environment and have a wide range of metabolic capabilities (Petri et al, 2013;Rubino et al, 2017). This metabolic flexibility likely explains the involvement of Prevotella in both primary and secondary colonization of feed as it can utilize soluble carbohydrates, pectins, proteins and hemicellulose .…”

Fecal microbiota transplantation as a tool to treat and reduce susceptibility to disease in animals

“…The rationale behind much of this interest is due to the knowledge that variation in feed efficiency between breeds or genetic lines of food producing animals likely has a gut microbial component, where certain livestock have gut microbes capable of harvesting energy from the diet at higher rates. Ribeiro et al (2017) investigated the interspecies transfer of bison rumen microbes to beef cattle in an effort to improve feed efficiency. The authors hypothesized that rumen microbes from bison may be more adapted to fiber digestion in low quality feedstuffs.…”

“…The authors hypothesized that rumen microbes from bison may be more adapted to fiber digestion in low quality feedstuffs. After removal of 70% of the endogenous rumen microbes in the recipient cattle, two transfaunates from bison resulted in increased nitrogen digestion and feed intake of the cattle, but did not affect fiber digestion of a barley straw diet (Ribeiro et al, 2017). In another study with poultry, FMT from highly feed-efficient donors was administered in the first several days of a chicken's life in an effort to enhance feed efficiency over subsequent weeks.…”