The objective of this investigation was to determine associations among rumen endotoxin, plasma serum amyloid A (SAA), and C-reactive protein (CRP) with plasma Ca, Fe, Zn, and Cu in lactating cows challenged with graded amounts of rolled barley grain in the diet (i.e., 0, 15, 30, and 45% of DMI). Correlative relationships among variables were determined by linear and nonlinear regression proced...

Scaling relationships between body mass and gut capacity are valuable to predicting digestive efficiency. Interspecific scaling relationships between body mass and gut capacity have consistently estimated a slope of 1.0; however, intraspecific scaling relationships between body mass and gut capacity have been highly variable. We examined the influence of demands of growth and production on scal...

The objective of the present study was to determine whether β1-4 galacto-oligosaccharides (GOS) and Candida kefyr combined with nitrate as manipulators could suppress rumen methanogenesis without nitrate poisoning in sheep. Four rumen fistulated wethers were allocated to a 4×4 Latin square design. Nitrate (1.3 g NaNO3 kg body weight) with and without GOS and Candida kefyr were administered into...

Accurate estimates of microbial synthesis in the rumen are vital to optimize ruminant nutrition. Liquid- (LAB) and solid-associated bacterial fractions (SAB) harvested from the rumen are generally considered as microbial references when microbial yield is calculated; however, factors that determine their composition are not completely understood. The aim of this study was to evaluate the effect...

A fed-batch, anaerobic culture system was developed to assess the behavior of Escherichia coli O157:H7 in a rumen-like environment. Fermentation medium consisted of either 50% (vol/vol) raw or sterile rumen fluid and 50% phosphate buffer. Additional rumen fluid was added twice per day, and samples were removed three times per day to simulate the exiting of digesta and microbes from the rumen en...

1. The dynamics of protozoa were studied in two groups of rumen-fistulated cattle fed on a basal diet of molasses ad lib., with oaten chaff given at 6 or 18 g/kg live weight. This diet resulted in different mixtures of protozoal species in the populations in the rumen. 2. The rumen protozoa were studied by intrarumen injections of protozoa labelled in vitro with [14CH3]choline. An indication of...

The rumen microbiome is integral to efficient production in cattle and shows strong host specificity, yet little is known about what host factors shape rumen microbial composition. Secretory immunoglobulin A (SIgA) is produced in large amounts in the saliva, can coat both commensal and pathogenic microbes within the gut, and presents a plausible mechanism of host specificity. However, the role ...

Anaerobic fungi were isolated from both the rumen and faeces of nine sheep and a cow. A reliable and simple method for the isolation of anaerobic fungi using 24 h rumen incubated milled straw as the inoculum source was developed. We also evaluate the use of chitin measurements as an assay of rumen fungal biomass. Chitin levels were determined from various sample sources (milled barley straw use...

Cattle manure is frequently used as an inoculum for the start-up of agricultural biogas plants or as a co-substrate in the anaerobic digestion of lignocellulosic feedstock. Ruminal microbiota are considered to be effective plant fiber degraders, but the microbes contained in manure do not necessarily reflect the rumen microbiome. The aim of this study was to compare the microbial community comp...

Four non-lactating, rumen-fistulated cows were fed ad lib. on two grass silages (first cut (FC) and second cut (SC) harvested at different growth stages, resulting in different crude-protein (CP) and neutral-detergent-fibre (NDF) contents (FC, 152g CP/kg, 515g NDF/kg and SC, 210g CP/kg, 442g NDF/kg). Voluntary intake and rumen contents, total as well as organic matter were higher for silage FC....