Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:6.3.4.6 (urease)
 7,490 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Sixty-four Angus steers initially averaging 354 kg were allotted to a 2 X 2 factorial arrangement of treatments to determine the effects of dietary Ni (0 or 5 mg/kg supplemental), monensin (0 or 33 mg/kg) and their possible interaction on performance, methane production and N metabolism. The basal diet was a high energy, corn-cottonseed hull based diet containing 10.2% crude protein and .30 mg/kg Ni on a dry matter basis. Monensin reduced (P less than .05) feed intake, did not affect average daily gain and improved (P less than .05) feed conversion over the 102-d study. Nickel supplementation did not significantly alter or interact with monensin to affect steer performance. However, steers fed Ni tended to have higher average daily gains and improved feed conversions. Monensin decreased (P less than .05) in vitro methane production, altered several carcass traits, increased (P less than .05) molar proportion of ruminal propionate and decreased (P less than .05) molar proportion of ruminal acetate. Nickel did not alter methane production, carcass characteristics or ruminal volatile fatty acid proportions. Both monensin and Ni increased (P less than .05) ruminal fluid urease activity when samples were obtained before feeding. A significant monensin X Ni interaction was found to affect ruminal epithelial urease activity. Monensin increased ruminal epithelial urease in steers not receiving supplemental Ni, but had no effect on ruminal epithelial urease activity in steers fed supplemental Ni. Ruminal fluid protein and ammonia-N were decreased (P less than .05) by monensin. Results of this study indicate that Ni may interact with monensin to affect ruminal epithelial urease activity but not performance or methane production in finishing steers.
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PMID:Performance, methanogenesis and nitrogen metabolism of finishing steers fed monensin and nickel. 357 Oct 11

1. A long-term experiment was made with the Rumen Simulation Technique (Rusitec), in which the fermentation of a mixed ration of hay (10 g/d) and bruised barley (5 g/d) was compared with the fermentation of the same diet in the presence of 2, 10 and 50 mg monensin/d. 2. Monensin depressed the production of acetic and butyric acids, markedly increased the production of propionic acid and virtually, eliminated the production of isovaleric acid. The production of methane was decreased in the presence of monensin, but this decrease could be accounted for entirely by the changes in the production of volatile fatty acids and redistribution of metabolic hydrogen. 3. The digestibility of dry matter (DM) in the rations declined in the presence of monensin. Determinations of the rates of digestion showed that the digestion of the readily-fermented food in the initial stages was not affected by monensin, but that at 24 h digestion had been inhibited by monensin. The inhibition was due entirely to its effect on the digestion of the fibrous components. Digestion of non-fibrous material was not affected. 4. The efficiency of microbial growth, expressed as g dry weight/mol ATP formed (YATP) and in terms of DM digested, tended to be increased by monensin. This however occurred only at high, non-practical doses. 5. Urease (EC 3. 5. 1. 5) was induced by the addition of urea of the fermentation, but monensin had no effect on urease activity. Although monensin increased the activity of protease in washed suspensions, more food protein apparently escaped degradation. This may have been due to decreased deaminative activity. 6. Monensin altered the microscopic appearance of the fermentation fluid, and changed the activity of some enzymes in sonicated extracts, including alkaline phosphatase (EC 3. 1. 3. 1), acetate kinase (EC 2. 7. 2. 1) and succinate dehydrogenase (EC 1. 3. 99. 1). These results are discussed in terms of known sensitivities of rumen microbes to monensin and their contribution to the fermentation as a whole.
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PMID:Effect of monensin on the fermentation of basal rations in the Rumen Simulation Technique (Rusitec). 702 Jul 49