I . Two pairs of Friesian steers were changed from ad lib. to restricted intake of a pelleted barley diet and were maintained on this latter intake for periods of 18 or 25 weeks. The restricted level of intake was 70 g/kg0-73 and was adjusted weekly according to individual live weights. The daily allowance was given in three equal feeds during day-time. 2. After an initial period of 9 weeks on ...

We used RNA probes and enzyme activities to compare the cellulolytic microbial ecosystems of the rumen and the cecum. Four rumen- and cecum-cannulated wethers were fed a diet of barley plus hay (60:40). Digesta samples were collected 1 h before feeding and 3, 6, and 9 h after feeding for measurements on microbial populations, and 1 h before feeding and 3 and 6 h after feeding for digestion meas...

Antibiotics can improve ruminant growth and efficiency by altering rumen fermentation via selective inhibition of microorganisms. However, antibiotic use is increasingly restricted due to concerns about the spread of antibiotic-resistance. Plant-based antimicrobials are alternatives to antibiotics in animal production. The hops plant (Humulus lupulus L.) produces a range of bioactive secondary ...

I. A study was made of the changes in electrolyte concentrations and ruminal function which resulted from the provision of 1.3 7; sodium chloride solutions instead of fresh water to sheep consuming roughage rations in chaffed and in ground pelleted forms. 2. Significantly higher osmotic pressures were observed in the rumen fluid of the sheep drinking saline water, the change being especially ma...

1. The activities of acetoacetyl-CoA thiolase, hydroxymethylglutaryl-CoA synthase and lyase and acetoacetyl-CoA deacylase were measured in homogenates of samples of liver, rumen epithelium (long papillae), kidney and lactating mammary gland derived from slaughtered cows. 2. The activities of the four enzymes in bovine liver were similar to the activities previously reported for the correspondin...

Short term in vitro incubations were used to evaluate the effect of fumaric acid bentonite coupled addition on rumen fermentation effeciency. Ruminal contents from five steers were used for preparation of inoculums of mixed rumen microorganisms that were used in generatation of three treatment systems, negative control, fumaric acid treated, and fumaric acid – bentonite coupled treated. The fer...

Urease (urea amidohydrolase, EC 3.5.1.5) was extracted from the mixed rumen bacterial fraction of bovine rumen contents and purified 60-fold by (NH4)2SO4 precipitation, calcium phosphate-gel adsorption and chromatography on hydroxyapatite. The purified enzyme had maximum activity at pH 8.0. The molecular weight was estimated to be 120000-130000. The Km for urea was 8.3 X 10(-4) M+/-1.7 X 10(-4)...

The supernatant from centrifugation at 1,000 x g of strained rumen fluid was lyophilized, and the residue and sublimate fractions were used to replace fresh rumen fluid in a complete roll tube medium for enumeration of total rumen bacteria. Most of the growth-supporting nutrients in fresh rumen fluid were found in the residue fraction. With one exception, no significant differences were found i...

From the simultaneous accumulation of hydrogenation intermediates and the disappearance of Isotricha prostoma after algae supplementation, we suggested a role of this ciliate and/or its associated bacteria in rumen biohydrogenation of unsaturated fatty acids. The experiments described here evaluated the role of I. prostoma and/or its associated endogenous and exogenous bacteria in rumen biohydr...

Six adult castrated male red deer (Cervus elaphus), fitted with rumen cannulas, were offered chaffed lucerne hay ad lib. during winter and summer, with voluntary food intake (VFI) being respectively 59 and 89 g dry matter intake (DMI)/kg bodyweight 0.75 per d. The same animals were also offered the same feed during summer, with intake restricted to that of winter VFI. The apparent digestibility...