1. In liver, rumen epithelium and kidney cortex of the sheep, a dehydrogenase active against dl-3-hydroxybutyrate occurred in both the cytosol and particulate fractions of the tissues. In brain, heart, skeletal and smooth muscles, the enzyme occurred only in the particulate fraction. 2. Enzyme activity in the cytoplasmic fraction of liver and rumen epithelium was similar with either d(-)-3-hydr...

The study examined the effects of harvest time of red and white clover silage on eating and ruminating activity and particle size distribution in feed boli, rumen content and faeces in cows. The clover crops were harvested at two stages of growth and ensiled in bales. Red clover crops had 36% and 45% NDF in dry matter (DM) at early (ER) and late (LR) harvest, respectively, and the white clover ...

BACKGROUND The rumen harbors a complex microbial ecosystem for efficient hydrolysis of plant polysaccharides which are the main constituent of the diet. Xylanase is crucial for hemicellulose hydrolysis and plays an important role in the plant cell wall degradation. Xylanases of ruminal strains were widely studied, but few studies have focused on their diversity in rumen microenvironment. METH...

this study was carried out to determine the potential of rumen microorganisms in samples taken from slaughterhouse to produce fibrolytic enzymes and to compare different methods for extraction, concentration and conservation of them.  according to the results, the average specific activity of cellulase and xylanase were 7.5 and 16.5 u/mg protein respectively. the application of homogenizing and...

Four ruminally cannulated cows were used to assess the distribution of the concentrations and carbohydrate-degrading enzyme activities of the liquid-associated protozoa (LAP) and solid-associated bacteria (SAB) in the rumen. The cows were fed diets (7 kg of DM/d) of 100% hay (Diet F) or 60% barley plus 40% hay (Diet C) in a 2 x 2 crossover experimental design. Samples of ruminal digesta were co...

Bacterial predation by protozoa has the most deleterious effect on the efficiency of N use within the rumen, but differences in activity among protozoal groups are not completely understood. Two in vitro experiments were conducted to identify the protozoal groups more closely related with rumen N metabolism. Rumen protozoa were harvested from cattle and 7 protozoal fractions were generated imme...

It has been known for decades that microbial fermentation within the rumen is critical to postnatal rumen epithelial growth and maturation in ruminants, but the underlying mechanism is largely unknown. In this study, we determined the effect of rumen fluid, which should contain all products from rumen fermentation, on growth of rumen epithelial cells in vitro. Addition of 10% rumen fluid from c...

The propert ies of rumen urease were studied. In the absence of high concentrations of dithiothreitol enzyme activity was rapidly lost; in its presence, the enzyme could be solubilized and purified in high yield. Maximum activity was observed between pH 7 and 8.5. The Km for urea with partially purified enzyme was .004 M with Vmax of 300 to 400 #moles/mg/hr. No divalent metal ion requirement or...

AIM A comparative study was conducted on crossbred cattle and buffaloes to investigate the effect of feeding high and low roughage total mixed ration (TMR) diets on rumen metabolites and enzymatic profiles. MATERIALS AND METHODS Three rumen-fistulated crossbred cattle and buffalo were randomly assigned as per 3×3 switch over design for 21-days. Three TMR diets consisting of concentrate mixtur...

The purpose of the present review is to examine the role played by nutrients in controlling feed intake in ruminants, in light of their particular anatomical, physiological, nutritional and behavioural characteristics. The ration is first digested in the rumen for several hours by microbial fermentation. Volatile fatty acids, which constitute 50-75% of a ruminant's energy supply, considerably d...