Protein available to ruminants is supplied by both microbial and dietary sources. Metabolizable protein (MP) is the true protein which is absorbed by the intestine and supplied by both microbial protein and protein which escapes degradation in the rumen; the protein which is available to the animal for maintenance, growth, fetal growth during gestation, and milk production. Thus, the concept of...

The origin of D-lactate, the most important acid contributing to metabolic acidosis in the diarrheic calf, is unknown. We hypothesized that because D-lactate is produced only by microbes, gastrointestinal fermentation is the source. The objective of this study was to determine whether D-lactate production occurs in the rumen, colon, or both, and to measure D- and L-lactate concentrations in uri...

Bovine digital dermatitis (DD) is the most important infectious disease associated with lameness in cattle worldwide. Since the disease was first described in 1974, a series of Treponema species concurrent with other microbes have been identified in DD lesions, suggesting a polymicrobial etiology. However, the pathogenesis of DD and the source of the causative microbes remain unclear. Here we c...

algae had no significant effect on DMD, CH4 or NH4–N (P>0.374), but lower CH4 emissions were generally observed with increasing protection level. Slower turnover rate and lower protection level may serve to promote toxic effects of the algae on rumen microbes, as indicated by the observed onset of floating digesta mat instability, which may reflect reduced production of fermentation gases (CH4 ...

Conventional measurements of Biological Value made from nitrogen absorption in the entire digestive tract are generally inappropriate when estimating the protein requirements of ruminants. Similarly, measurements in rats, of the Biological Value of rumen microbes cannot be applied with confidence to ruminants. A direct measurement of the Biological Value of absorbed amino acids is required, and...

this experiment was conducted to investigate the effects of garlic powder on fermentation characteristic and rumen microbes of arabian sheep.at first step the best level of garlic was determined. then animals were fed for 35 days with control diet and supplemented with garlic (2% per kg dm). apparent digestibility, rumen fermentation parameters, number of protozoa and blood metabolites (glucose...

Hydrogen (H2) is an essential substrate for methanogens to produce methane (CH4), and also influences pathways of volatile fatty acids (VFA) production in the rumen. Dissolved H2 (H2 (aq)) is the form of H2 available to microbes, and dissolved CH4 (CH4 (aq)) is important for indicating methanogens activity. Rumen H2 (aq) concentration has been estimated by assuming equilibrium with headspace ga...

Several studies have revealed differences in rumen-located microbes between greatly efficient and inefficient animals; however, how the microbiota vary in the hind gastrointestinal tract (GIT) has only been sparsely explored and how they vary in the small intestine remains to be determined. We therefore sampled the microbiota of the duodenum, jejunum, ileum, colon, and colorectally-obtained fec...