Hydrogen is a key product of rumen fermentation and has been suggested to thermodynamically control the production of the various volatile fatty acids (VFA). Previous studies, however, have not accounted for the fact that only thermodynamic near-equilibrium conditions control the magnitude of reaction rate. Furthermore, the role of NAD, which is affected by hydrogen partial pressure (PH2), has ...

Twelve ruminally cannulated Holstein calves (age, 12 ± 3 weeks) were used to identify the effect of a probiotic comprised of Lactobacillus plantarum, Enterococcus faecium and Clostridium butyricum on ruminal components. The calves were adapted to a diet containing a 50% high-concentrate (standard diet) for 1 week, and then, the probiotic was given once daily for 5 days (day 1-5) at 1.5 or 3.0 g...

Five crossbred steers (347 kg) were surgically fitted with rumen fistulae, hepatic portal, abdominal aorta and mesenteric catheters to measure organic acid absorption from the gut during acute [intraruminal glucose, 12 g/kg body weight (G)] or subacute [ad libitum 70% concentrate diet (C)] acidosis. Samples were taken at time 0, then every 2 h for 48 h after a switch from an alfalfa diet to C, ...

Responses to sugars in dry or liquid form vary from study to study. To explain some of this variation and prioritize when sugars are more likely to have a benefit in diets for high producing dairy cattle, microbial function that influences susceptibility to low ruminal pH or a limitation in growth factors needed for efficient ruminal fiber degradation is discussed in this paper. When fed in pro...

The effect of substituting native grass with jengkol (Archidendron jiringa) by-product on fermentation characteristics, rumen microbial profile, methane production, and hydrogen balance using in vitro method was investigated. Seven treatments (different composition of native grass, jengkol peel, jengkol leaves, and concentrate) with five replications in a block randomized desi...

The objective of this study was to investigate the effect of banana flower powder (BAFLOP) supplementation on gas production kinetics and rumen fermentation efficiency in in vitro incubation with different ratios of roughage to concentrate in swamp buffalo and cattle rumen fluid. Two male, rumen fistulated dairy steers and swamp buffaloes were used as rumen fluid donors. The treatments were arr...

in this experiment, different doses of zataria multiflora (zm) and eucalyptus globolus (eg) essential oils (eos) (0, 100, 250, 500, 750 and 1000 µg/ml) and a mixture of them were added to alfalfa hay incubated with buffered rumen liquor of merghoz goat to assess in vitro gas production, rumen fermentation and protozoa population. in all treatments the asymptotic gas volume (b) and the rate cons...

One of the largest challenges for the dairy industry is to provide cows with a diet which is highly energetic but does not negatively affect their rumens' functions. In highly productive dairy cows, feeding diets rich in readily fermentable carbohydrates provides energy precursors needed for maximum milk production, but simultaneously decreases ruminal pH, leading to a widespread prevalence of ...

Eight ruminally fistulated steers were utilized to evaluate the effects of amount of dried distillers grains (DDG) supplementation on forage dry matter intake (DMI), digestibility, and rumen parameters in steers consuming bermudagrass round bale silage (RBS). Treatments consisted of RBS only or RBS plus daily supplementation of DDG at 0.33, 0.66, or 1.0% of bodyweight (BW). There was quadratic ...

The cellulolytic activity of rumen contents was assayed by measuring losses in weight and tensile strength of cotton yarn incubated in rumen contents in the presence of dietary additives (barley, tallow) and at different pH values. The addition of barley depressed cellulolysis and the titer of filter paper-degrading bacteria only if the pH was allowed to fall. Lowering the pH from 7.0 to 6.0 by...