Eight crossbred (75% Holstein Friesian) cows in mid-lactation were randomly assigned to a switchback design with a 2x2 factorial arrangement to evaluate two nonstructural carbohydrate (NSC) sources (corn meal and cassava chips) with different rumen degradability and used at two levels of NSC (55 vs. 75%) with protein source (supplied by urea in the concentrate mix). The treatments were 1) Low d...

Ruminant herbivores utilize a symbiotic relationship with microorganisms in their rumen to exploit fibrous foods for nutrition. We report the metagenome sequences of the greater kudu (Tragelaphus strepsiceros) rumen digesta, revealing a diverse community of microbes and some novel hydrolytic enzymes.

Research on rumen microorganisms has contributed greatly to our understanding of anaerobic microbial ecosystems, and has also influenced feeding practices and nutritional modelling with ruminants. However, it can be argued that rumen microbiology has not yet fulfilled its true potential. Growth-promoting ionophores, antibiotics and microbial feed additives were introduced before their microbiol...

Lignin-carbohydrate complexes (LCCs) are recognised as key structures in forage degradability. Apart from ester bonds involving phenolic acids, which seem to play a major role in grasses, little is known about the other types of linkages that must exist but have proved difficult to demonstrate. The chemical nature of possible LCC linkages is presented and the various mechanisms through which LC...

Protozoa-associated methanogens (PAM) are considered one of the most active communities in the rumen methanogenesis. This experiment investigated whether methanogens are sequestrated within rumen protozoa, and structural differences between rumen free-living methanogens and PAM. Rumen protozoa were harvested from totally faunated sheep, and six protozoal fractions (plus free-living microorganis...

The aim of this study was to evaluate the effects of adding sulfuric acid to sugarcane tops silage on rumen bacteria and whole rumen microorganisms (WRM) and compare the digestibility of sugarcane tops treated with different amount of urea, molasses and sulfuric acid between Holstein cow and Khouzestan buffalo. Regardless of the type of the treatment, potential of gas production (B) by cow WRM ...

It is well known that rumen fermentation processes play a key role in ruminant nutrition, as it is this distinctive symbiotic feature between the host and the rumen microflora that lends the ruminant animal several advantages in digestive and metabolic processes over non-ruminants. The extent of complexity of interactions between diverse groups of microorganisms which inhabit the rumen is such ...

Samples of rumen digesta were collected from 2 cows fed with a 100:0 or 40:60 forage/concentrate diet 1 h before and 2 h after feeding. Enzymes from particle-associated microorganisms were extracted by 5 different methods, including physical (freezing, grinding and sonication) or chemical and enzymatic (autolysis in a buffer, lysozyme and CCl4) treatments. Hydrolytic enzyme activities were meas...

It has been established that the digestion of carbohydrates in the ruminant occurs mainly through the agency of the micro-organisms of the alimentary tract. The evidence for this subject has been reviewed by Elsden & Phillipson (1948) and Baker & Harriss (1947-8). Most of this digestion occurs in the rumen. Of the cellulose of the diet about 80 yo of the total digested disappears in the rumen, ...