the aim of this study was to determine effects of different fatty acid profiles on rumen digestion coefficients, some of rumen metabolism parameters and rumen microbial populations. different oils were used as source of fatty acids such as, oleic, linoleic, linolenic, dha and epa. palmitic acid supplemented from a commercial product (bergafat t-300) containing high palmitic acid percentage. res...

A highly rapid, one-step immunoassay of high sensitivity C-reactive protein (hsCRP) using a biosensor with a vertical flow immunoassay (VFA) was developed. The VFA biosensor was primarily composed of a sample pad, conjugate pad, FTH film and nitrocellulose (NC) membrane, which were all vertically stacked upon one another. Anti-hsCRP and secondary antibodies were consecutively immobilized on the...

A bench-scale study on swine manure stabilization for odour control was conducted using batch aeration reactors. In trial 1, two aeration lengths, i.e., 0.5 and 4.0 day, were used under uncontrolled ambient temperature that increased gradually over the experimental period. While in trial 2, a 16.0-day aeration scheme was employed under constant 17 degrees C. An airflow rate of 1.2L/s/m(3) was u...

An in vitro rumen batch culture study was completed to compare effects of common grasses, leguminous shrubs and non-leguminous shrubs used for livestock grazing in Australia and Ghana on CH4 production and fermentation characteristics. Grass species included Andropodon gayanus, Brachiaria ruziziensis and Pennisetum purpureum. Leguminous shrub species included Cajanus cajan, Cratylia argentea, G...

Simple logic control algorithms were tested for automatic control of a lab-scale CSTR manure digester. Using an online VFA monitoring system, propionate concentration in the reactor was used as parameter for control of the biogas process. The propionate concentration was kept below a threshold of 10 mM by manipulating the feed flow. Other online parameters such as pH, biogas production, total V...

Background The sustainability of microbial lipids production from traditional carbon sources, such as glucose or glycerol, is problematic given the high price of raw materials. Considerable efforts have been directed to minimize the cost and find new alternative carbon sources. Volatile fatty acids (VFAs) are especially attractive raw materials, because they can be produced from a variety of or...

The objective of this study was to investigate the effect of the pattern of concentrate-rich feeding on subacute ruminal acidosis (SARA), its severity, and the corresponding changes in VFA concentration. Eight rumen-cannulated Holstein cows were assigned to a 2 × 2 crossover design with 2 SARA challenge models and 2 experimental runs ( = 8 per treatment). Each run lasted for 40 d, consisting of...

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...

1. The present paper reports the effects on rumen fermentation and plasma metabolites and hormones of giving fixed rations of hay and high-cereal concentrates at different meal frequencies to lactating cows. In Expt 1 the total ration was given in two and twenty-four meals daily and in Expts 2-4 the concentrates were given in two and five or six meals and the hay in two meals daily. The diets c...

Recent articles by van Winsen et al. (2001) (16) and van der Wielen et al. (2000) (14) have described the measurements of lactate and volatile fatty acids (VFA) in the hind guts (ceca and colons) of pigs and broiler chickens, respectively, in an attempt to link these concentrations with the growth of certain pathogenic bacteria. In broiler chickens, the concentrations of lactate and acetate in ...